Remove bootstrap-responsive.css

In `components/bootstrap` version `>= 3.0` the bootstrap-responsive.css does not exist.

Author: loostro

Resources/views/base_admin.html.twig

@@ -25,7 +25,6 @@
     {% block stylesheets %}
         {% stylesheets filter='cssrewrite,?yui_css' output='assetic/css/compiled/components.min.css'
             'components/bootstrap/css/bootstrap.css'
-            'components/bootstrap/css/bootstrap-responsive.css'
             'components/bootstrap/css/bootstrap-theme.css'
             'components/font-awesome/css/font-awesome.css'
         %}