Create user account

[lhoogenraad]

There should be a route at POST /api/signup that allows users to create an account in letterbookd with an email and password.

Once successfully signed up, this route should return a jwt auth token to the requester.

req body example:

{
    email: "le.o.n@outlok.com",
    password: "password123",
    firstName: "Leon",
    lastName: "Something",
}

[lhoogenraad]

A critical part of this feature is using bcrypt (or some other hashing function) to encrypt user passwords as soon as they enter the server.

[lhoogenraad]

Boom!