v3.0.0

[yusuftor]

This is the official v3 release. No more RCs, woohoo!

Changes in this pull request

The following have changed since rc7:

• Fixes a crash if handleDeepLink(_:) is called twice.
• Changes the PaywallInfo closeReason to be non-nil with a .none case. This is so it can be compatible with Objective-C.
• Renames the SWKGetPaywallResult paywallViewController property to paywall.
• Exposes info on the PaywallViewController in Objective-C
• Fully handles what happens when there is no internet/network issues.
• Reenables the loading of subscription group ids if using a purchase controller.
• Exposes togglePaywallSpinner publicly for the PaywallViewController.
• Stops any presentation result checkers from accidentally loading the webview.
• Fixes issue where paywall requests weren't being cached.

However, for a full list of changes in v3, see our changelog.

Checklist

• [x] All tests pass. Demo project builds and runs.
• [x] I added tests, an experiment, or detailed why my change isn't tested.
• [x] I added an entry to the CHANGELOG.md for any breaking changes, enhancements, or bug fixes.
• [x] I have run swiftlint in the main directory and fixed any issues.
• [x] I have updated the SDK documentation as well as the online docs.
• [x] I have reviewed the contributing guide