Add date-ranges to some posts

Conflicts:
	blog/_posts/2015-05-28-birthday-holidays.md

_layouts/post.html

@@ -16,6 +16,9 @@
             <span itemprop="name">{{ page.title }}</span>
             <small class="print-only" itemprop="datePublished" content="{{ page.date|date:'%F') }}">{{ page.date|date:'%A, %B %d, %Y' }}</small>
         </h1>
+        {% if page.end_date %}
+            <span class="date-range">&#x1f557; {{ page.date|date:"%d/%m/%Y" }} - {{ page.end_date|date:"%d/%m/%Y" }}</span>
+        {% endif %}
     </header>
     <section class="post-content" itemprop="articleBody">
         {{ content }}
@@ -24,4 +27,4 @@
         {% include disqus.html %}
     {% endif %}
 </section>
-{% include footer.html %}
+{% include footer.html %}