message: cache bundler in addition to travis on ci
diff: language: rust
  dist: xenial
  -cache: cargo
  env:
  RUSTINFRA_DEPLOY_DIR: _site
  import:
  - rust-lang/simpleinfra/travis-configs/static-websites.yml@travis-configs
  +cache:
  + directories:
  + # cache: cargo
  + - $HOME/.cargo
  + - $TRAVIS_BUILD_DIR/target
  + # cache: bundler
  + - $TRAVIS_BUILD_DIR/vendor/bundle
  +
  install:
  - bundle install
  