v0.17.7 - such PRs
wowe

From @tamird:
- Use File.writable_real? to avoid a questionable ruby stdlib group write access check

From @schnittchen:
- Work around a superflous ruby warning when Dir.chdir is used

From @bearded:
- Fix boolean defaults passed to accepts_*_for declarations
- Remove unused String#colorize! start_at arg
- Fix the rubinius entries in .travis.yml

From @santouras:
- Run via sudo when required when adding apt ppas.

From @Val:
- Add a version declaration for debian-7.3, and then debian-7.4
  (This shouldn't be necessary, I'll refactor it someday)