function bunker(fn) {
    try {
      fn();
    } catch (e) {
      if (!PRODUCTION) {
        throw e;
      }
    }
  }
Font Awesome 4 used the prefix of `fa` for all icons. With the introduction
of new styles we needed to differentiate between them. Prefix `fa` is now an alias
for `fas` so we'll easy the upgrade process for our users by automatically defining
this as well.