Run rustfmt and clippy on CI

Signed-off-by: Victor Porof <victor.porof@gmail.com>

.travis.yml

@@ -14,7 +14,18 @@ rust:
   - beta
   - nightly
 
+before_script:
+  # We install a known-to-have-rustfmt version of the nightly toolchain
+  # in order to run the nightly version of rustfmt, which supports rules
+  # that we depend upon. When updating, pick a suitable nightly version
+  # from https://rust-lang.github.io/rustup-components-history/
+  - rustup toolchain install nightly-2019-09-11
+  - rustup component add rustfmt --toolchain nightly-2019-09-11
+  - rustup component add clippy --toolchain nightly-2019-09-11
+
 script:
+  - cargo +nightly-2019-09-11 fmt --all -- --check
+  - cargo +nightly-2019-09-11 clippy --all-features -- -D warnings -A clippy::match-ref-pats -A clippy::needless-lifetimes
   - cargo build --verbose
   - export RUST_BACKTRACE=1
   - cargo test --all --verbose