Check differences between source data and the database

[zkagin]

Depends on #96
Fixes #85

Adds "diffing" logic to check the differences between source data and the database, and returns data that should either be deleted/archived or created.

Tests pass and should cover the corner cases I can think of so far.

A few notes for future cleanup:

• Right now the CourseAliases object gets created from within the Base, which is not a great pattern. Eventually I'd like to refactor this so that a Controller object creates all of the endpoints and can then pass in the Aliases information that is needed.
• The clearing of databases in the test suite should happen in a teardown() function rather than in the test itself, but I haven't yet found a good way to clear the whole database. Until I do that, just dropping the table from the associated endpoint seems to work well enough.

[dchess]

@zkagin Had a chance to test this out this morning and the results look good. Although we wouldn't want to use the to_delete portion for courses (only students).

However, when I try running the test suite locally I am getting a failed test for the to_create assertion (line 170 of test_all.py).

[dchess]

@zkagin Switching this to merge to main now that it is the default branch instead of master.

[zkagin]

Good catch, I changed something in the code and it did break the tests (the columns are different). Concerningly, while the check correctly runs the test and the test correctly fails, the check itself passes even though it has this:

app_1       | ========================= 1 failed, 15 passed in 8.00s =========================
google_classroom_app_1 exited with code 1
Stopping google_classroom_database_1 ... 

Stopping google_classroom_database_1 ... done
Aborting on container exit...
Removing google_classroom_app_1      ... 
Removing google_classroom_database_1 ... 

Removing google_classroom_app_1      ... done

Removing google_classroom_database_1 ... done
Removing network google_classroom_default

The exit code 1 should cause the check to fail. I'll try and dig into it, but for now I'll make sure to manually run tests before I submit.

[zkagin]

@dchess For the time being I will run tests manually to make sure they pass until I can figure out what's going on with the Github Action.

This should be ready for your review again.