We need to add authentication middleware to our main API so that we can be sure that our API is being accessed only by authenticated users.

Acceptance criteria
Unauthenticated users can't access the API.

To Do

• create a separate submodule called httputil
• add authentication middleware in there
• connect that submodule to main API and apply authentication
• modify unit tests
• move things from main API to htttputil

Notes
We can base the middleware on this code. But we no longer need IP authentication, so that we can simplify the code.