test: use monkeypatch to safely handle monekypatching Tests are unittest based, so pytest fixtures can not be used by adding them to the function signature. Augment the inject_fixtures to inject monkeypatch as self._monkeypatch. Use _monkeypatch to patch the three functions replacing the code that manually did the patch. Remove the code that rolls back the manual patching as monkeypatch rolls it back automatically when the test function exits.

[roundup_test_db]
host=127.0.0.1
port=5432
user=rounduptest
password=rounduptest
dbname=rounduptest

[roundup_test_schema]
host=127.0.0.1
port=5432
user=rounduptest_schema
password=rounduptest
dbname=rounduptest_schema
options=-c search_path=roundup_service_dev

[roundup_test_schema_bad]
host=127.0.0.1
port=5432
user=rounduptest_schema
password=rounduptest
dbname=rounduptest_schema
options=-c search_path=