clippy: add clippy lints

This doesn't fail the build currently but they are available
for reference.

Signed-off-by: Paul Osborne <[email protected]>

Author: posborne

.travis.yml

@@ -9,4 +9,10 @@ rust:
 
 script:
   - cargo test
+  - |
+      if [ "${TRAVIS_RUST_VERSION}" = "nightly" ]; then
+         cargo install --git https://github.com/arcnmx/cargo-clippy
+         cargo clippy --lib --features lints
+         cargo clippy --bin gpio --features lints
+      fi
   - cargo doc

Cargo.lock

@@ -12,6 +12,16 @@ glob = "0.2"
 log = "0.3"
 env_logger = "0.3"
 
+[dependencies.clippy]
+version = "*"
+git = "https://github.com/Manishearth/rust-clippy"
+rev = "master"
+optional = true
+
+[features]
+default = []
+lints = ["clippy"]
+
 [[bin]]
 name = "gpio"
 path = "src/main.rs"