Test Hole: No test failing for line 180 of date.py when a change should have caused a test failure.

[wxtim]

In https://github.com/metomi/isodatetime/pull/165/files we changed the name of two functions used by Rose, but only one test seems to fail as a result of the changes:

• set_time_zone_to_local becoming to_local_time_zone
• set_time_zone_to_utc becoming to_utc

Apparently failing because of change of name of set_time_zone_to_local.

However the occurrence of set_time_zone_to_utc at line 180 of metomi/rose/date.py doesn't cause any tests to fail - we should probably make sure that this code is covered by tests.

[MetRonnie]

(Now on L182) https://github.com/metomi/rose/blob/78e730522a488f471beaec0526fa7fbfab6f81f7/metomi/rose/date.py#L181-L182