Adds CocoaPods 1.2.0 to Travis (which provides 1.1.1 right now)

[emilianbold]

Travis builds seems to be failing since we upgraded Cocoapods.

From the log I see they have 1.1.1 and according to their documentation we might need to manually install the newer version

Note how I kept adding commits because other things broke:

• pods not found
• the watchos dependency confusing xcodebuild
• a newer XCode image needed for some frameworks

I'm pleased with the PR now. Please review.