Providing git credentials for each test creation

[ili-shmidt-wib]

Describe the enhancement you'd like to see

1. For each git test that is created - a git username and token must be provided. My suggestion is that the credentials would be provided only once and the tests will retrieve it.

2. The response from '/v1/tests' endpoint contains the credentials in plain-text. My suggestion is not to return the credentials at all or return the reference to the credentials.