add clippy to travis integration

Author: rloomba

.travis.yml

@@ -22,6 +22,10 @@ script:
      - if [ "$BUILD_NET_TOKIO" == "1" ]; then RUSTFLAGS="-C link-dead-code" cargo build --verbose; fi
      - if [ "$BUILD_NET_TOKIO" != "1" ]; then RUSTFLAGS="-C link-dead-code" cargo build --verbose -p lightning; fi
      - rm -f target/debug/lightning-* # Make sure we drop old test binaries
+     # Run clippy on Rust 1.39.0
+     - if [ "$(rustup show | grep default | grep 1.39.0)" != "" ]; then
+           rustup component add clippy &&
+           cargo clippy -- -Aclippy::erasing_op -Aclippy::never_loop -Aclippy::if_same_then_else; fi
      # Test the appropriate workspace(s)
      - if [ "$BUILD_NET_TOKIO" == "1" ]; then RUSTFLAGS="-C link-dead-code" cargo test --verbose; fi
      - if [ "$BUILD_NET_TOKIO" != "1" ]; then RUSTFLAGS="-C link-dead-code" cargo test --verbose -p lightning; fi

CONTRIBUTING.md

@@ -77,6 +77,17 @@ Coding Conventions
 Use tabs. If you want to align lines, use spaces. Any desired alignment should
 display fine at any tab-length display setting.
 
+Please lint your code using [clippy](https://github.com/rust-lang/rust-clippy).
+
+```bash
+rustup component add clippy
+cargo clippy
+```
+
+We use the [default linting settings](https://rust-lang.github.io/rust-clippy/rust-1.39.0/index.html), which includes all lint
+groups except for nursery, pedantic, and cargo. Our CI will use these default settings in addition to allowing the
+following lints: `erasing_op`, `never_loop`, `if_same_then_else`.
+
 Security
 --------
 

lightning/src/lib.rs

@@ -36,4 +36,3 @@ pub mod util;
 pub mod chain;
 pub mod ln;
 pub mod routing;
-

lightning/src/ln/channelmanager.rs

@@ -16,6 +16,7 @@
 //! It does not manage routing logic (see routing::router::get_route for that) nor does it manage constructing
 //! on-chain transactions (it only monitors the chain to watch for any force-closes that might
 //! imply it needs to fail HTLCs/payments/channels it manages).
+//!
 
 use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::constants::genesis_block;