Remove version caps

[cbrnr]

Currently, all versions are capped, because the caret ^ operator also introduces an upper bound. In this PR, I replaced ^ with >=, which continues to use the same lower bounds, but removes any upper bound.

[tompollard]

Thanks @cbrnr, please could you rebase? Not immediately clear why the tests are failing. Looks like they are failing on a style issue in a chunk of unrelated code?

[cbrnr]

Done. It's because the previous pandas-related change interferred with these modifications.

[tompollard]

@bemoody Please could you add your thoughts on this PR? I see that SoundFile is explicitly pinning an upper bound (SoundFile = ">=0.10.0, <0.12.0"), which I assume is intentional? Does this need to stay?

@cbrnr Presumably the change to Black is causing the tests to fail. We need to look into what's happening there!

[cbrnr]

I've fixed all Black issues, these were related to empty lines that shouldn't be there. Seems like they updated their style guide, because I noticed the same in one of my projects recently.

Let me know about the SoundFile version. If you really need to keep <0.12.0, we should add a test.

[tompollard]

Thanks @cbrnr, looks good to me! @bemoody?

[tompollard]

@bemoody is happy