Add Apache 2.0 License

Open-source library, allowing for oss and commercial use with Apache 2.0
license.
Adds some incidental common development folders to .gitignore
Merge pull request #1 from jackcviers/add-license

Add Apache 2.0 License
Add Chefspec tests.

[Chefspec](https://github.com/sethvargo/chefspec) is an rspec extension
for chef recipe unit testing.

It allows you to develop the cookbook in a TDD manner, and without having to
run `vagrant up` to see recipe compilation issues.