travis: Add clippy

.travis.yml

@@ -32,7 +32,8 @@ before_script:
 
 script:
   - cargo fmt -- --write-mode=diff
-  - travis-cargo build
+  - travis-cargo --skip nightly build
+  - travis-cargo --only nightly build -- --features "clippy"
   - travis-cargo --only stable doc -- --no-deps
 
 after_success:

Cargo.toml

@@ -8,6 +8,7 @@ wayland-server = "0.8.4"
 nix = "0.7.0"
 slog = { version = "~1.5.2", features = ["max_level_trace", "release_max_level_info"] }
 slog-stdlog = "~1.1.0"
+clippy = { version = "*", optional = true }
 
 [dev-dependencies]
 slog-term = "~1.5"

src/lib.rs

@@ -1,5 +1,8 @@
 #![warn(missing_docs)]
 
+#![cfg_attr(feature = "clippy", feature(plugin))]
+#![cfg_attr(feature = "clippy", plugin(clippy))]
+
 #[macro_use]
 extern crate wayland_server;
 extern crate nix;