remove dockerized, setup Heroku deployment, update TravisCI config

.gitignore

.travis.yml

Procfile

docker-compose.yml

oser-backend/.dockerignore

oser-backend/Dockerfile

oser-backend/oser_backend/core/migrations/0001_initial.py

...end/oser_backend/showcase_site/migrations/0001_initial.py

...end/oser_backend/showcase_site/migrations/0002_partner.py

...ckend/showcase_site/migrations/0003_auto_20180304_1417.py

...ckend/showcase_site/migrations/0004_auto_20180304_1418.py

...r_backend/showcase_site/migrations/0005_partner_active.py

...ckend/showcase_site/migrations/0006_auto_20180304_2026.py

oser-backend/oser_backend/tutoring/__init__.py

...-backend/oser_backend/tutoring/migrations/0001_initial.py

...er_backend/tutoring/migrations/0002_auto_20180301_2332.py

oser-backend/oser_backend/tutoring/migrations/__init__.py

oser-backend/oser_backend/users/__init__.py

oser-backend/oser_backend/users/migrations/0001_initial.py

oser-backend/oser_backend/users/migrations/__init__.py