Use sprockets-rails 2.0.0.rc4
Revert "Merge pull request #10043 from cconstantine/master"

This reverts commit 521035af530482d6d9ad2dae568eaeb0ab188e1c, reversing
changes made to 222011dbee842bbc60d3aaaa3145356b90a30fd1.

Reason: This broke the tests
Better ordering
HTML5 breaks
Indent around the scaffold loop
Unindent attributes iteration in scaffold index template

Otherwise we get extra indent for the <td> elements due to the extra
spaces at the beginning of the lines, like this:

      <tr>
          <td><%= author.name %></td>
          <td><%= link_to 'Show', author %></td>
        <td><%= link_to 'Edit', edit_author_path(author) %></td>