Refactor

As all points from the epic refactor issue are closed #47 (closed) I am merging this in to master in order to unblock development.

backend/requirements.txt

@@ -7,3 +7,4 @@ psycopg2~=2.7.1
 xlrd~=1.0.0
 pytest-cov~=2.5.1
 pylint~=1.7.4
+django-cors-headers~=2.1.0