Drop Chef 11 support

[majormoses]

With chef 13 being released and all the chef community cookbooks somewhat recently dropped chef < 12.1 support I think it's time to rip the bandaid off and do a major release. Yes I am sure that quite a few people will complain but we must think what is best for the community. They will still be able to use it in it's existing form by pinning to 1.x but those with newer chef setups can benefit from newer features. We should add a section for this in the readme.