Icon setup mixin

@mixin icon-setup($icon, $width, $height, $padding:"") {
      padding-left: $width + 9;
      position: relative;
      &:before {
        @include icon-sprite($icon);
        content: '';
        display: inline-block;
        height: $height;
        left: 5px;
        position: absolute;
        @if $padding == '' {
          top: 0;
        } @else {
          top: $padding;
        }
        width: $width;
      }
    }