Run Rustfmt and make formatting error fail the CI

Author: josephlr

.travis.yml

@@ -181,10 +181,6 @@ matrix:
       script:
         - cargo fmt --all -- */*.rs --check
 
-  allow_failures:
-    # Formatting errors should appear in Travis, but not break the build.
-    - name: "rustfmt"
-
 before_install:
   - set -e
   - rustup self update

src/lib.rs

@@ -269,7 +269,7 @@ cfg_if! {
 /// [`rand::thread_rng`](https://docs.rs/rand/*/rand/fn.thread_rng.html).
 pub fn getrandom(dest: &mut [u8]) -> Result<(), error::Error> {
     if dest.is_empty() {
-        return Ok(())
+        return Ok(());
     }
     imp::getrandom_inner(dest)
 }