Fix different package casing in tests

[uranusjr]

The most simple cases

[pfmoore]

Doing it this way, these tests will start failing again when the new resolver becomes default. Instead, we should do a case insensitive test (assuming we're not going to fix the reporting to use the case the user entered). So assert 'whatever, all in lowercase' in script.stdout.lower().

We could be more clever, I guess, but that should be sufficient...

[pfmoore]

It still looks ugly TBH, but it does the job, which is the main thing.

(We really shouldn't be testing for exact content of error messages like this, but that's a problem for another day).

[pfmoore]

We actually raise the wrong exception here, which is why the messages still didn't match. I'm preparing a new fix (using re to only make the package name case insensitive, because I'm picky 🙂).