Carthage build pulling in PromiseKit 6.8.x

[m11m]

My app was crashing and I'm pretty sure it was because Carthage was pulling in AwaitKit 6.8.3.

dyld: lazy symbol binding failed: Symbol not found: _$S10PromiseKit8ThenablePAAE4then2on5flags_AA0A0Cy1TQyd__GSo17OS_dispatch_queueCSg_8Dispatch0J13WorkItemFlagsVSgqd__AIQzKctAaBRd__lFfA0_
  Referenced from: Frameworks/AwaitKit.framework/AwaitKit
  Expected in: Frameworks/PromiseKit.framework/PromiseKit

dyld: Symbol not found: _$S10PromiseKit8ThenablePAAE4then2on5flags_AA0A0Cy1TQyd__GSo17OS_dispatch_queueCSg_8Dispatch0J13WorkItemFlagsVSgqd__AIQzKctAaBRd__lFfA0_
  Referenced from: Frameworks/AwaitKit.framework/AwaitKit
  Expected in: Frameworks/PromiseKit.framework/PromiseKit

I added the following to my Cartfile and the issue was resolved.

github "mxcl/PromiseKit" == 6.7.1

Thought you might like to know, Thanks, cool library. :)