Remove dependency of live URLs/endpoints for unit tests

[michaelgira23]

In our unit tests, we must fill out this test config file in order to pass the tests. While this should be important to test once in a while, all of the current maintainers do not attend MyMICDS and therefore do not have ready access to an up-to-date portal/canvas URL. We should save a cache of these (maybe deanonymize the data?) and pretend that is the live URL. That way, we can run all the tests offline.

This will have compounding effects on developer productivity when we need to fix bugs, to make sure we don't cause a regression in functionality.