Update .travis.yml

Added coocapods caching hints
Merge pull request #68 from sgtsquiggs/master

Add travis hints for cocoapods caching
Avoid naming clash between example and resource bundle scheme.
Merge pull request #82 from CocoaPods/fix-issue-81

Avoid naming clash between example and resource bundle scheme.
Travis: Bump CocoaPods version

- Travis is not always on latest CocoaPods
- Use --project-directory instead of `cd -`