Add different permission levels

At the moment there is only one permission level.

Acceptance:

1. Viewer (CAiMIRA dashboard)
   • Can view parameter values and history
   • Only access to the GET data endpoints
2. Expert (The "updater" that calls the API for a certain freq.)
   • Can update "static" parameters, i.e. parameters that are not being updated by a job.
   • Only access to the "update" endpoint
3. Administrator (Administrative dashboard user)
   • Can configure update jobs
   • Access to all endpoints