Add mongoose and migrations

[Moniarchy]

As a developer, I want to be able to specify database migrations for use during deployment, so that I can safely create and revert database updates.

• Should integrate with Mongoose (if appropriate)
• Must allow data migrations
• Must create a /test/db endpoint that demonstrates how to store (POST) and retrieve (GET) information from the DB
• Must include a .env file, with DATABASE_URL specified and used for mongo connection

[Moniarchy]

In progress