Show template stats even if there’s only 1 row

If you’re only ever sending one template it’s really useful to be able
to jump straight to that template from the dashboard. So this commit:
- shows the template stats even if there’s only one row
- hides the bar chart if there’s only one row (because it will always be
  100%, and won’t be obvious what it is without its siblings)

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

@@ -11,10 +11,14 @@
       </dt>
 
       <dd class="column-half">
+        {% if template_statistics|length > 1 %}
         <span class="spark-bar">
           <span style="width: {{ item.usage_count / most_used_template_count * 100 }}%"></span>    
           {{ item.usage_count }} {{ message_count_label(item.usage_count, item.template.template_type) }}
         </span>
+        {% else %}
+          {{ item.usage_count }} {{ message_count_label(item.usage_count, item.template.template_type) }}
+        {% endif %}
       </dd>
 
     </div>

app/templates/views/dashboard/today.html

@@ -40,7 +40,7 @@
     </div>
   </div>
   
-  {% if template_statistics|length > 1 %}
+  {% if template_statistics|length %}
     {% include 'views/dashboard/template-statistics.html' %}
     {{ show_more(
       url_for('.template_history', service_id=current_service.id),