Remove unnecessary clippy lint annotations

We moved to "cargo clippy" in 5ba34d4f97 and
removing the clippy lint annotations in `src/lib.rs` does not cause any additional warnings.

This also changes `cargo clippy` to use the flags required for checking integration tests.

.travis.yml

@@ -29,5 +29,5 @@ matrix:
     - rust: nightly
 
 script:
-  - if [ -n "$CLIPPY" ]; then cargo clippy; fi
+  - if [ -n "$CLIPPY" ]; then cargo clippy --all-features --all-targets; fi
   - if [ -z "$CLIPPY" ]; then cargo test; fi

src/lib.rs

@@ -110,9 +110,6 @@ impl Mul<f32> for Rgb {
 }
 
 
-#[cfg_attr(feature = "clippy", allow(too_many_arguments))]
-#[cfg_attr(feature = "clippy", allow(doc_markdown))]
-#[cfg_attr(feature = "clippy", allow(unreadable_literal))]
 #[allow(unused_mut)]
 pub mod gl {
     #![allow(non_upper_case_globals)]

src/util.rs

@@ -15,7 +15,6 @@ use std::cmp;
 
 #[cfg(not(feature = "nightly"))]
 #[inline(always)]
-#[cfg_attr(feature = "clippy", allow(inline_always))]
 pub unsafe fn unlikely(x: bool) -> bool {
     x
 }