Add contribution guidance

Add CONTRIBUTING.md that points to the same document in chef-cookbooks
Add mention of the contribution document in the top of the README.md
Merge pull request #4 from claco/contributing

Merged automatically by jenkins after successful build test
Version Bump to 4.1.3
Merge pull request #6 from rackerjoe/master

Version Bump to 4.1.3
Merge branch 'v4.1.3rc' into grizzly

Conflicts:
	metadata.rb