Added closing figure tag to resolve issue #577. (#579)

Added a closing `</figure>` tag in `quote_block.html` to fix the HTML
structure and resolve #577.

coderedcms/templates/coderedcms/blocks/quote_block.html

@@ -6,4 +6,5 @@
 {% if self.author %}
 <figcaption class="blockquote-footer">{{self.author}}</figcaption>
 {% endif %}
+</figure>
 {% endblock %}