clearfix SASS Mixin

// http://nicolasgallagher.com/micro-clearfix-hack/
@mixin clearfix {
// For modern browsers
  &:before,
  &:after {
    content:" ";
    display:table;
  }

  &:after {
    clear:both;
  }

  // For IE 6/7 (trigger hasLayout)
  & {
    *zoom:1;
  }
}