Don't ignore Podfile.lock

This file holds information about the exact dependency versions
installed with `pod install`. In the case that one of the dependencies
were updated with API breaking versions it would still be installed.
Check in xcworkspace

Don't ignore the xcworkspace created by CocoaPods. Since your
dependencies, installed through CocoaPods, are required to build this
project, you shouldn't ignore the required workspace.
Merge pull request #1 from Keithbsmiley/ks-cocoapods

Update .gitignore for CocoaPods
Add CONTRIBUTING file
Rename CONTRIBUTING -> CONTRIBUTING.md
Add very basic example config.plist
Update Podfile.lock
Update KernelTests path in Rakefile
Remove cache entries on error. Deny writes to files with pending executions