Add support for async/await

[tahirmt]

• I have read CONTRIBUTING and have done my best to follow them.

What did you do?

I think we should add support for swift Concurrency framework (async/await) especially now that it has been back deployed to iOS 13 and macOS 10.15.

Environment

List the software versions you're using:

• Quick: 3.0.0
• Nimble: 9.0.0
• Xcode Version: 13.2 (13C90) (Open Xcode; In menubar: Xcode > About Xcode)
• Swift Version: Xcode Default (Open Xcode Preferences; Components > Toolchains. If none, use Xcode Default.)

Please also mention which package manager you used and its version. Delete the
other package managers in this list:

• Swift Package Manager 5.5.0 (swiftpm-???) (Use swift build --version in Terminal)

[tahirmt]

Closing this since we already have Quick/Quick#1084

[CraigSiemens]

I think this could stay open as Nimble would also need its own changes to properly support swift concurrency. For example expect(...) doesnt support being passed an awaiting function call.

[tahirmt]

That’s a good point. I’ll reopen.

[younata]

This was addressed in #1004!