Remove constraints on time-entry creation

[enriquezrene]

A time entry needs to be created as soon as the user clicks on a project. In the same way, that it is happening on t-sheets right now. So, we need to remove some required fields during a time-entry creation.

The only fields we have are going to be:

• JWT (injected in headers)
• project_id
• start_date

Acceptance Criteria
The following request can be executed with no problems:

curl -X POST "http://timetracker-api.azurewebsites.net/time-entries" -H "accept: application/json" -H "Content-Type: application/json" -d "{ \"project_id\": \"390d9d3a-ed2e-4d9a-bb28-2e633c1fbbb9\", \"start_date\": \"2020-04-17T00:50:37.201229\"}"

[EliuX]

This is probably what #86 is about.

Regarding to the required fields:

• The activity_id was required in the model graph. It was a required foreign key before (RFK), but as you requested, I removed it to just foreign key (FK).
• JWT is not a requirement for the model, and that is part of the authentication mechanism which is not defined.
  Please @enriquezrene confirm that the solution for Remove constraints on time-entry creation #87 suites your needs. If so close this ticket.

[EliuX]

I tested it and it worked.