Create an API for adding a new game to the database.

[Treyhesari]

This story depends on #4.

As a user, I want to be able to add an entirely new game to the list of games known by this project.

Acceptance Criteria:

• Get current game counts for a user curl localhost:8080/games
• Add a new game record: curl -H 'Authentication: Bearer <token>' -H 'Content-Type: application/json' -d $some-json-payload -X POST localhost:8080/games where $some-json-payload is a valid JSON payload, and <token> is a valid JWT
• See that the game has been created: curl localhost:8080/game/:some-game-id where :some-game-id is the new game's slug

Implementation Notes:

• Should have basic validation (e.g. the given game slug exists, etc)
• The final route and payload to POST to is up to the implementer (and we will update the Acceptance Criteria to match)