Add view for a single template

> At the moment, we have an all email templates page, and an edit an
> individual page.
>
> This gets messy when we refer to templates like the dashboard and the
> activity views. We solve this currently by using anchor links to the
> list page, but this is clunky.
>
> So lets add it, then update the links on the dash and activity to the
> new view page.
>
> Should be a link from the view a single template page, to the template
> hub page.

https://www.pivotaltracker.com/story/show/117349227

app/templates/views/dashboard/template-statistics.html

@@ -6,7 +6,7 @@
   field_headings=['Template', hidden_field_heading('Type'), right_aligned_field_heading('Messages sent')]
 ) %}
   {% call field() %}
-    <a href="{{ url_for('.edit_service_template', service_id=current_service.id, template_id=item.template.id) }}">
+    <a href="{{ url_for('.view_template', service_id=current_service.id, template_id=item.template.id) }}">
       {{ item.template.name }}
     </a>
   {% endcall %}