Initial API endpoint to be used for future shenanigans

This is an api endpoint for SeAT to allow external applications to authenticate against the api. There isn't currently a front-end for managing applications, but you can in the seat_api_applications table if you want to have a play with this until I figure out how to present some of the info.

Example output can be seen here:

https://gist.github.com/t3rminalVel0city/a2d31609c1f0e3fb8076