The rest of RubyGems doesn't have a space following "(" or "[" nor preceding "]" nor ")".  Normally I would clean up such things myself, but for this pull request there's way too much of it.

Overall this expression concerns me.  Like line 287, why is basic_authentication cleaning up after load_credentials by making sure the `:basic_auth` key is present?  It seems the responsibility here is misplaced.