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

Bump xcconfig version

G6 hotfix (LoopKit#1014)

* Update carthage to use g6 hotfix

* Bump version for hotfix release

* Use CGMBLEKit v3.1