rustup
rustup

This commit builds on the latest Rust nightly, but the `regex` crate
hasn't been updated yet.

brandonson/docopt.rs,brandonson/docopt.rs,zsiciarz/docopt.rs,birkenfeld/docopt.rs,zsiciarz/docopt.rs,birkenfeld/docopt.rs,brandonson/docopt.rs,birkenfeld/docopt.rs,zsiciarz/docopt.rs