Add persona include.js to dashboard

I screwed up when I un-super()'d things before and missed this. Without
this, persona login doesn't work.

fjord/analytics/templates/analytics/dashboard.html

@@ -6,6 +6,7 @@
 
 {% block site_js %}
   {{ js('dashboard') }}
+  <script type="text/javascript" src="https://login.persona.org/include.js"></script>
 {% endblock %}
 
 {% macro feedback_block(feedback) -%}