removed extra colon in discussion

Author: ShadenSmith

_layouts/tensor_layout.html

@@ -87,6 +87,6 @@ <h3>Citation</h3>
 
 {{ content }}
 
-<h3 style="padding-top: 60px">Discussion:</h3>
+<h3 style="padding-top: 60px">Discussion</h3>
 {% include comments.html %}