add heroku files

Author: bbengfort

Procfile

@@ -0,0 +1 @@
+web: gunicorn app:app --log-file -

runtime.txt

@@ -0,0 +1 @@
+python-3.7.3

templates/index.html

@@ -124,5 +124,14 @@ <h5 class="modal-title" id="aboutModalLabel">About Data Space</h5>
   <script src="{{ url_for('static', filename='js/dataspace.js') }}"></script>
 
   <!-- google analytics -->
+  <script async src="https://www.googletagmanager.com/gtag/js?id=UA-8096804-15"></script>
+  <script>
+    window.dataLayer = window.dataLayer || [];
+    function gtag() { dataLayer.push(arguments); }
+    gtag('js', new Date());
+
+    gtag('config', 'UA-8096804-15');
+  </script>
+
 </body>
 </html>