add testing structure and example test

[diegoac2]

find an appropriate test structure and add tests

[navarroc]

For this task, let's keep it as simple as possible.

1. Find a test layout we like to get the folder structure defined
2. Add a single test to test "something", even if it's not relevant to the service, just to verify the tests run correctly.
3. Add a Github action to run the test. See pyincore pytest.yml for an example.