Full spec coverage + fixes

- Refactor old specs + add new ones for full coverage
- Updated README, LICENSE and Versionfile
- Fixed missing locale keys and untranslated mail template
- Add Swedish locale
- Use .add_routes instead of .draw
- Separated assets (js, css) so they not required
- Permit attr :remark
- Applied @j27lee fixes for finder deprecation warnings
- Use variant.can_supply? instead of .in_stock?
- Updated Travis so it do not spam IRC