Replace beta banner with beta badge

This is part of the new header style that Tim, Stephen et al have been
working on.

This means that we lose the feedback link, so I’m trying out having it
in the top right.

app/templates/admin_template.html

@@ -31,6 +31,7 @@
 {% endblock %}
 
 {% block inside_header %}
+  <strong class='beta-badge'>Beta</strong>
 {% endblock %}
 {% block header_class %}with-proposition{% endblock %}
 {% block proposition_header %}
@@ -39,6 +40,7 @@
       <a href="#proposition-links" class="js-header-toggle menu">Menu</a>
       <nav id="proposition-menu">
         <ul id="proposition-links">
+          <li><a href="{{ url_for('main.feedback') }}">Support and feedback</a></li>
           {% if current_user.is_authenticated %}
             <li>
               <a href="{{ url_for('main.user_profile') }}">{{ current_user.name }}</a>