diff --git a/.gitignore b/.gitignore
index 847709f..5551cda 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 target
 tmp
+Cargo.lock
diff --git a/Cargo.lock b/Cargo.lock
deleted file mode 100644
index 38a98ec..0000000
--- a/Cargo.lock
+++ /dev/null
@@ -1,295 +0,0 @@
-[[package]]
-name = "aho-corasick"
-version = "0.6.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "atty"
-version = "0.2.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "bitflags"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "byteorder"
-version = "1.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "cfg-if"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "chrono"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-integer 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "time 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "core_io"
-version = "0.1.20180307"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "env_logger"
-version = "0.5.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "atty 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "fatfs"
-version = "0.2.0"
-dependencies = [
- "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "byteorder 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "chrono 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "core_io 0.1.20180307 (registry+https://github.com/rust-lang/crates.io-index)",
- "env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "humantime"
-version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "quick-error 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "lazy_static"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "libc"
-version = "0.2.40"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "log"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "memchr"
-version = "2.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-integer"
-version = "0.1.36"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-traits"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "quick-error"
-version = "1.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "redox_syscall"
-version = "0.1.37"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "redox_termios"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "redox_syscall 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "regex"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "regex-syntax"
-version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "rustc_version"
-version = "0.1.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "semver 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "semver"
-version = "0.1.20"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "termcolor"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "wincolor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "termion"
-version = "1.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "redox_syscall 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
- "redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "thread_local"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "time"
-version = "0.1.39"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "redox_syscall 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "ucd-util"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "unreachable"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "utf8-ranges"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "void"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "winapi"
-version = "0.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "winapi-i686-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "winapi-x86_64-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "wincolor"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[metadata]
-"checksum aho-corasick 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d6531d44de723825aa81398a6415283229725a00fa30713812ab9323faa82fc4"
-"checksum atty 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)" = "2fc4a1aa4c24c0718a250f0681885c1af91419d242f29eb8f2ab28502d80dbd1"
-"checksum bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d0c54bb8f454c567f21197eefcdbf5679d0bd99f2ddbe52e84c77061952e6789"
-"checksum byteorder 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "73b5bdfe7ee3ad0b99c9801d58807a9dbc9e09196365b0203853b99889ab3c87"
-"checksum cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "405216fd8fe65f718daa7102ea808a946b6ce40c742998fbfd3463645552de18"
-"checksum chrono 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1cce36c92cb605414e9b824f866f5babe0a0368e39ea07393b9b63cf3844c0e6"
-"checksum core_io 0.1.20180307 (registry+https://github.com/rust-lang/crates.io-index)" = "52c2fc3ad457529bd2ac28471ffc4d8971656de79d3b5fb745ba8117c7c997cc"
-"checksum env_logger 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "0e6e40ebb0e66918a37b38c7acab4e10d299e0463fe2af5d29b9cc86710cfd2a"
-"checksum humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0484fda3e7007f2a4a0d9c3a703ca38c71c54c55602ce4660c419fd32e188c9e"
-"checksum lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c8f31047daa365f19be14b47c29df4f7c3b581832407daabe6ae77397619237d"
-"checksum libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)" = "6fd41f331ac7c5b8ac259b8bf82c75c0fb2e469bbf37d2becbba9a6a2221965b"
-"checksum log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "89f010e843f2b1a31dbd316b3b8d443758bc634bed37aabade59c686d644e0a2"
-"checksum memchr 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "796fba70e76612589ed2ce7f45282f5af869e0fdd7cc6199fa1aa1f1d591ba9d"
-"checksum num-integer 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)" = "f8d26da319fb45674985c78f1d1caf99aa4941f785d384a2ae36d0740bc3e2fe"
-"checksum num-traits 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dee092fcdf725aee04dd7da1d21debff559237d49ef1cb3e69bcb8ece44c7364"
-"checksum quick-error 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "eda5fe9b71976e62bc81b781206aaa076401769b2143379d3eb2118388babac4"
-"checksum redox_syscall 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)" = "0d92eecebad22b767915e4d529f89f28ee96dbbf5a4810d2b844373f136417fd"
-"checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
-"checksum regex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "75ecf88252dce580404a22444fc7d626c01815debba56a7f4f536772a5ff19d3"
-"checksum regex-syntax 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8f1ac0f60d675cc6cf13a20ec076568254472551051ad5dd050364d70671bf6b"
-"checksum rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "c5f5376ea5e30ce23c03eb77cbe4962b988deead10910c372b226388b594c084"
-"checksum semver 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)" = "d4f410fedcf71af0345d7607d246e7ad15faaadd49d240ee3b24e5dc21a820ac"
-"checksum termcolor 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "adc4587ead41bf016f11af03e55a624c06568b5a19db4e90fde573d805074f83"
-"checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
-"checksum thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279ef31c19ededf577bfd12dfae728040a21f635b06a24cd670ff510edd38963"
-"checksum time 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "a15375f1df02096fb3317256ce2cee6a1f42fc84ea5ad5fc8c421cfe40c73098"
-"checksum ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fd2be2d6639d0f8fe6cdda291ad456e23629558d466e2789d2c3e9892bda285d"
-"checksum unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
-"checksum utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "662fab6525a98beff2921d7f61a39e7d59e0b425ebc7d0d9e66d316e55124122"
-"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
-"checksum winapi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "04e3bd221fcbe8a271359c04f21a76db7d0c6028862d1bb5512d85e1e2eb5bb3"
-"checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
-"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-"checksum wincolor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "eeb06499a3a4d44302791052df005d5232b927ed1a9658146d842165c4de7767"