bug #39 [Backend] remove unused admin.css. (aitboudad)

This PR was merged into the master branch.

Discussion
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[Backend] remove unused admin.css.

Commits
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f224d8c [Backend] fixed unused css/admin.css.

Author: javiereguiluz

app/Resources/views/admin/layout.html.twig

@@ -1,13 +1,5 @@
 {% extends 'base.html.twig' %}
 
-{% block stylesheets %}
-    {# this 'parent()' function allows to maintain any stylesheet previously
-       included from 'base.html.twig' simplifying style management #}
-    {{ parent() }}
-
-    <link rel="stylesheet" type="text/css" href="{{ asset('css/admin.css') }}">
-{% endblock %}
-
 {% block header_navigation_links %}
     <li>
         <a href="{{ path('admin_post_index') }}">