33 endpoints for posts

[rdhillon1016]

In this PR:

• Created skeleton for the posts route
• Separated out validation and queries
• Changed a lot of the callback syntax for auth to async/await (fixes some weird errors with regards to error throwing like when the calling function goes out of scope which means the try-catch is no longer available, and then the callback is executed and throws an error which crashes the app)

Not done yet:

• Complete rest of posts route
• Make the error handling better (see https://expressjs.com/en/guide/using-middleware.html )
• Add some unit tests (supertest?)