Integrated Postgresql Database!! :D

Used the psycopg2 library to integrate a postgresql database. Also wrote a few unit tests for the Database class and a few functional tests. Set up a CI/CD pipeline through Travis-CI and Heroku by adding a .travis.yml file. Saved the dependencies to requirements.txt so that `pip install -r requirements.txt` works. Also added gunicorn and a Procfile so that Heroku (and you) can use `foreman start` to start up the server.

I wrote some stuff in the README.md to help with setting up the project :)

Also, the database version is currently live at http://musictest-dev.herokuapp.com
The current version doesn't have any way of viewing the results from the website (maybe the next step?), but you can view the results by going to your database in heroku and running the command that looks like `heroku pg:psql COLOR` from terminal and running sql statements there.

Let me know your thoughts or if you have any questions!