Use bundle exec.
Update dev dependencies.
Add support for Hound CI.
Test only 2.1.x on master branch.
Bye bye hash rockets and overflow newlines.
Change all common cop offenses.
Skip some cops.
Update layout for master branch.

Still some tweaks can be made to the public stars layout.
Fullscreen mode when run Capybara with selenium.
Refactor Settings.

Settings where broken and had an ugly hack for accepting boolean
preferences. It was initialized using a non standard pattern. Also add
:show_identifier to form and locales.
Move loose NB_STARS constant into preferences.
Fixes broken specs.
tmp folder to .gitignore.
Add CHANGELOG.md and bump version.
Simplify .recalculate_rating

This also removes cop offenses.