use maintained fork of typeahead library

I noticed while investigating a bug that the typeahead library is
essentially abandoned:

twitter/typeahead.js#1232

One of the comments in the above thread mentions this fork of the
library, which is actively maintained and includes a fix for said bug.

views/index.html

@@ -8,7 +8,7 @@
     <!-- all this, just for typeahead :( -->
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-tagsinput/0.8.0/bootstrap-tagsinput.css" />
     <script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/typeahead.js/0.11.1/typeahead.bundle.min.js"></script>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/corejs-typeahead/1.1.1/typeahead.bundle.min.js"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-tagsinput/0.8.0/bootstrap-tagsinput.min.js"></script>
 
     <link rel="stylesheet" href="/static/index.css" />