Add test for checkLat/checkLon and test checkers/converters are triggered
This is in preparation of the re-factoring done in I28895b6cc94e87af68f88b455ef2a431d4b5f00a .
The longitude tests are almost identical to the latitude tests since the
two calls don't share any code (yet). It should be possible to do this in
a better way but I'm unsure how this would trigger setUp() tearDown() calls.
Note that this includes the test_trigger_problematic_check which is
expected to fail once the re-factoring is done.
- Make TestLookupSourceField use differently named source/dest values for clarity. And as a result changed function name.
- Change all assert_called_with to assert_called_once_with to make it explicit that only a single call is expected.
- Add test for lat_no_lon and lon_no_lat warnings.