Dj-stripe: Release 2.1.0

[therefromhere]

With the SCA rules coming into effect very shortly I'd like to get the 2.1.0 release live as soon as we're fairly confident that we won't need to make any breaking changes (ie migrations).

I think we're nearly there, see outstanding issues on the 2.1.0 milestone, please shout out if you have an issue that looks like it'll require breaking changes.

I've added a new 2.1.x milestone for issues that we'd like to fix soon but don't look like they're blockers on a 2.1.0 release and are unlikely to require migrations.

My plan for release is to do a migration squash as per the docs prior to release.

Please note if you've been running the 2.1.0dev branch that you'll need to migrate with the squashed migration before upgrading to the 2.1.0 release - I'm thinking it might be useful to release this commit as a 2.1.0rc package to make this easier for people?

Thanks to everyone who's contributed to this release!

[tasn]

I like the idea of having an rc that is essentially the release but for people who used master and need to apply migrations. Good idea!

[therefromhere]

OK, think we're nearly there, I've got through the new models in the API and make a few tweaks (see #912 and linked PRs).

I'll try running this in a prod-like environment probably tomorrow, if it looks good I'll merge #990 to squash migrations, release that as 2.1.0rc, and then release 2.1.0 fairly soon afterwards.

[therefromhere]

I've released 2.1.0rc0 with the migration squash (see 33db6e9787bf443a66fcd5c24bdf6648dfba9f18).

[therefromhere]

2.1.0 is live now, thanks to everyone who contributed!