Create user object in database on signin #54
Description
If a user signs in for the first time, a new user object should be created and saved to the database.
- Generate a new user_id. This can just be an increasing counter, as it's just an identifier, not a security feature.
- Populate the necessary fields automatically (name, email, etc.). Rest should be left blank.
- Update timestamps as needed.
If an existing user signs in, don't create new object.
- Verify that the access tokens and auth stuff is still valid. If not, generate new ones.
- Update the lastLogin timestamp.