message: feat(RadioGroup): has a shadow to make interactability more clear
  ISSUES CLOSED:
diff: @import './../../scss/helpers/layout';
  @import './../../scss/helpers/reset';
  @import './../../scss/helpers/spacing';
  +@import './../../scss/helpers/shadows';
  @import './../../scss/helpers/typography';
  // <label> container for a single option
  .c-radio__control {
  + @include elevation-element(raised-button);
  @include responsive-ratio(1, 1);
  overflow: hidden;
  padding: spacing(default);
  