Center Workbook titles to match all site headers

Author: jordanmccullough

_layouts/workbook.html

@@ -3,9 +3,10 @@
 theme: workbook
 ---
 
-<section class="hero">
+<section class="hero center">
   <div class="container">
-    <span class="octicon octicon-book"></span><h1>{{ page.title }}</h1>
+<!--     <span class="octicon octicon-book"></span> -->
+    <h1>{{ page.title }}</h1>
     {% include license.html %}
   </div>
 </section>