Removes $btn-hover variable
Cleans up button styles to fix #148
Removes $btn-hover from random helper file
Merge pull request #152 from DoSomething/buttons

Flat Button Styles
Build for production before testing/linting. Fixes #120.
Merge pull request #153 from DoSomething/deploy-error

Build for production before testing/linting. Fixes #120.
Release v3.0.11