Add mock csv dict reader

[FacundoMainere]

In the future, the local csv will change, so we need example data in our repo that doesn't change so it will be used for tests. And in test we have to replace the normal csv reader with the mocked one with the fixed example data.

[FacundoMainere]

Well, there seems to be an issue with running the whole test suite.

pytest -v tests

fails because the mocks are not applying

When running each test file the mocks apply and the tests succeed:
pytest -v tests/test_routes.py

So.. it's really weird, if someone knows whats going on, i would really want to know whats happening.