Merge pull request carpentries#174 from IanLee1521/fix-episode-nav-wrapping

Fix episode nav wrapping

Author: rgaiacs

_includes/episode_navbar.html

@@ -2,22 +2,22 @@
   Navigation bar for an episode.
 {% endcomment %}
 <div class="row">
-  <div class="col-md-1">
-    <h3>
+  <div class="col-xs-1">
+    <h3 class="text-left">
       {% if page.previous.url %}
       <a href="{{ page.root }}{{ page.previous.url }}"><span class="glyphicon glyphicon-menu-left" aria-hidden="true"></span><span class="sr-only">previous episode</span></a>
       {% else %}
       <a href="{{ page.root }}/"><span class="glyphicon glyphicon-menu-up" aria-hidden="true"></span><span class="sr-only">lesson home</span></a>
       {% endif %}
     </h3>
   </div>
-  <div class="col-md-10">
+  <div class="col-xs-10">
     {% if include.episode_navbar_title %}
     <h3 class="maintitle"><a href="{{ page.root }}/">{{ site.title }}</a></h3>
     {% endif %}
   </div>
-  <div class="col-md-1">
-    <h3>
+  <div class="col-xs-1">
+    <h3 class="text-right">
       {% if page.next.url %}
       <a href="{{ page.root }}{{ page.next.url }}"><span class="glyphicon glyphicon-menu-right" aria-hidden="true"></span><span class="sr-only">next episode</span></a>
       {% else %}