Hints (#232)

* Switching to Flask-Migrate to create tables/database. Adding Hints & Unlocks.
* Adding db.create_all call for sqlite db's (sqlite is not properly handled with alembic yet)
* Python 3 testing works properly with 3.5
* Adding admin side of hints
* Hints are viewable for users

tests/test_user_facing.py

@@ -203,5 +203,5 @@ def test_viewing_challenges():
         client = login_as_user(app)
         gen_challenge(app.db)
         r = client.get('/chals')
-        chals = json.loads(r.data)
-        assert len(chals['game']) == 1
+        chals = json.loads(r.get_data(as_text=True))
+        assert len(chals['game']) == 1