Refactoring and updating of unit tests

[fleimgruber]

Proposal to move unit tests to the conventional top level tests directory. For a first draft, please see fleimgruber@4fe0fb7. I tried to separate into tests related to domains and clients. Is the test code still relevant or does it need to be adapted due to internal API changes? E.g. for test_domains I get 9 tests passing and one failing like this (because of binary string vs. str):

FAILED          [ 10%]
tests\test_clients.py:23 (EntsoeRawClientTest.test_basic_queries)
self = <tests.test_clients.EntsoeRawClientTest testMethod=test_basic_queries>

    def test_basic_queries(self):
        queries = [
            self.client.query_day_ahead_prices,
            self.client.query_load,
            self.client.query_wind_and_solar_forecast,
            self.client.query_load_forecast,
            self.client.query_generation,
            self.client.query_generation_forecast,
            self.client.query_installed_generation_capacity,
            self.client.query_imbalance_prices
        ]
        for query in queries:
            text = query(country_code=self.country_code, start=self.start,
                         end=self.end)
>           self.assertIsInstance(text, str)
E           AssertionError: b'PK\x03\x04\x14\x00\x08\x08\x08\x00...' is not an instance of <class 'str'>

test_clients.py:38: AssertionError

[fboerman]

hi @fleimgruber this seems like a good idea. Could you provide a pull request for it?

[fleimgruber]

@fboerman please see #131.

[fboerman]

hi @fleimgruber thank you lets move the discussion to there