removed unused imports, added necessary.

src/libbuild_zynq/lib.rs

@@ -1,8 +1,5 @@
-use std::env;
 use std::fs::File;
-use std::io::Write;
 use std::io::{BufRead, BufReader};
-use std::path::PathBuf;
 
 pub fn cfg() {
     // Handle rustc-cfg file

src/runtime/build.rs

@@ -1,5 +1,6 @@
 use std::env;
 use std::fs::File;
+use std::io::Write;
 use std::path::PathBuf;
 
 extern crate build_zynq;

src/satman/build.rs

@@ -1,5 +1,6 @@
 use std::env;
 use std::fs::File;
+use std::io::Write;
 use std::path::PathBuf;
 
 extern crate build_zynq;