Keep installed tools up-to-date using cargo-update

Author: phil-opp

.travis.yml

@@ -9,8 +9,10 @@ before_script:
   - curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain=$TRAVIS_RUST_VERSION -y
   - source ~/.cargo/env
   - rustup component add rust-src
+  - (test -x $HOME/.cargo/bin/cargo-install-update || cargo install cargo-update)
   - (test -x $HOME/.cargo/bin/rustfmt || cargo install rustfmt)
   - (test -x $HOME/.cargo/bin/xargo || cargo install xargo)
+  - cargo install-update -a
 
 sudo: false