Merge pull request #52 from bvssvni/master

Upgraded to latest Rust
Fix Vacant/Occupied imports
Fix travis before_script commands

rustc exits non-zero when given the `-v` flag and no input files. I'm
guessing it's supposed to be `-V`?
Merge pull request #54 from bheart/master

Fix Vacant/Occupied imports
Removed `rustc/cargo -v` from .travis.yml

See https://github.com/PistonDevelopers/piston/issues/794