Bring in LoopKit updates for 2.2.6 patch

Bump rileylink_ios rev

Update rileylink_ios to use pinned carthage

Use embedded carthage binary

Update travis to use xcode12

Merge pull request LoopKit#1397 from LoopKit/dev

Release 2.2.4

Merge pull request LoopKit#1390 from LoopKit/dev

Release 2.2.3

Bump version

Fix release version

Merge pull request LoopKit#1305 from LoopKit/dev

Release 2.2