Update the Assembla tests to use the new hosting service test helpers.
Review Request #9780 — Created March 14, 2018 and submitted — Latest diff uploaded
This updates the Assembla test suite to use the new helpers for hosting
service unit tests, which provide better, more consistent checks with
simpler code and less private method usage. It also raises better
messages when skipping tests due to lack of Perforce support.
Unit tests pass.