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 [ "$(rustup show | grep default | grep 1.39.0)" != "" ]; then
+           rustup component add clippy &&
+           cargo clippy; fi
      # Test the appropriate workspace(s)
      - if [ "$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

lightning/src/lib.rs

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

lightning/src/ln/channel.rs

@@ -6,6 +6,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
 // You may not use this file except in accordance with one or both of these
 // licenses.
+#![allow(clippy::erasing_op)]
 
 use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::script::{Script,Builder};

lightning/src/ln/channelmanager.rs

@@ -16,6 +16,8 @@
 //! 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).
+//!
+#![allow(clippy::never_loop)]
 
 use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::constants::genesis_block;

lightning/src/routing/network_graph.rs

@@ -9,6 +9,8 @@
 
 //! The top-level network map tracking logic lives here.
 
+#![allow(clippy::if_same_then_else)]
+
 use bitcoin::secp256k1::key::PublicKey;
 use bitcoin::secp256k1::Secp256k1;
 use bitcoin::secp256k1;

lightning/src/util/byte_utils.rs

@@ -6,6 +6,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
 // You may not use this file except in accordance with one or both of these
 // licenses.
+#![allow(clippy::erasing_op)]
 
 #[inline]
 pub fn slice_to_be16(v: &[u8]) -> u16 {