remove unused code
improve readme
Merge branch 'master' of https://github.com/tmwagency/kickoff

# By Ashley Nolan
# Via Ashley Nolan
* 'master' of https://github.com/tmwagency/kickoff:
  Changing lots of class names to be more SMACCS like
  Updating keyframe mixin, deleting some obsolete variables and adding in box-sizing for before and after elements