Use `assert_relative_eq!` instead of relative_eq!`.

When testing for something, need to use the assert form.

src/geometry/dual_quaternion.rs

@@ -97,7 +97,7 @@ where
     ///
     /// let dq_normalized = dq.normalize();
     ///
-    /// relative_eq!(dq_normalized.real.norm(), 1.0);
+    /// assert_relative_eq!(dq_normalized.real.norm(), 1.0);
     /// ```
     #[inline]
     #[must_use = "Did you mean to use normalize_mut()?"]
@@ -122,7 +122,7 @@ where
     ///
     /// dq.normalize_mut();
     ///
-    /// relative_eq!(dq.real.norm(), 1.0);
+    /// assert_relative_eq!(dq.real.norm(), 1.0);
     /// ```
     #[inline]
     pub fn normalize_mut(&mut self) -> T {

src/geometry/quaternion.rs

@@ -138,7 +138,7 @@ where
     /// # use nalgebra::Quaternion;
     /// let q = Quaternion::new(1.0, 2.0, 3.0, 4.0);
     /// let q_normalized = q.normalize();
-    /// relative_eq!(q_normalized.norm(), 1.0);
+    /// assert_relative_eq!(q_normalized.norm(), 1.0);
     /// ```
     #[inline]
     #[must_use = "Did you mean to use normalize_mut()?"]

src/lib.rs

@@ -36,8 +36,8 @@ fn main() {
     let angle = 1.57;
     let b     = Rotation3::from_axis_angle(&axis, angle);
 
-    relative_eq!(b.axis().unwrap(), axis);
+    assert_relative_eq!(b.axis().unwrap(), axis);
-    relative_eq!(b.angle(), angle);
+    assert_relative_eq!(b.angle(), angle);
 }
 ```