[Gemfile] Update clintegracon
[Spec][Integration] Compare YAML files pretty printed
[TargetIntegrator] Ensure the project is saved when needed

Addresses a regression introduced in https://github.com/CocoaPods/CocoaPods/pull/2601
[Style] Don't use reduce to determine if there are changes

Use a var instead, as per @alloy
Merge pull request #2606 from CocoaPods/clintegracon_patch

Update to new CLIntegracon Patch
[gemspec] Bump cocoapods-trunk
[Gemspec] Require Resolver
[Resolver] Start using the resolver gem!
[Resolver] Add rudimentary lockfile handling, equivalent to the old behavior