* Update Makefile
* Optionally load test DB from env variable
* Add option to soft-delete a user
This allows users to be marked as deleted.
An additional middleware checks if a user is deleted or deactivated and rejects
requests for those as StatusUnauthorized.
note: the middelware adds an additional DB query to load the user.
* remove cmd folder as we are going to have only one entrypoint
* get rid of pkg directory
* rename test -> integration_tests as unit tests should reside next to the actual files they are testing
* database migration WIP
* reinstate gorm boilerplate in the addinvoice for now to make it compile
* introduce migrations
* add Makefile
* don't use unsigned types for database mappings
* migrations work now
* add build target
* use echo groups
* gorm removed
* add envconfig
* fix comments
