Updates CocoaLumberjack dependency

#### Problem:

*pod update* fails due to a dependency issue: Crashlytics requires CocoaLumberjack version >= 1.9 (cool right?).

#### Fix!

Since CocoaLumberjack is being used in all of our pods, i've submitted few pull requests bumping up the version:

- [WordPress-iOS Shared Pull Request](https://github.com/wordpress-mobile/WordPress-iOS-Shared/pull/43)
- [WordPress-iOS Editor Pull Request](https://github.com/wordpress-mobile/WordPress-iOS-Editor/pull/375)
- [WordPress-iOS Stats Pull Request](https://github.com/wordpress-mobile/WordPressCom-Stats-iOS/pull/63)

#### Please: 
1. Merge the above
2. Release new Pod versions (for all of them!)
3. Poke me in slack, so we can bump up the pods dependencies.

Thanks in advance!

Closes #2768 

/cc @sendhil