Fix up berkshelf brokeness

 This fix removes the Berksfile.lock. That file is what `berks upload` uses to resolve the versions it should upload. There are 2 reasons I removed the file. 1. It was wrong 2. It currently specifies the full path to local cookbooks. It should be relative.

This fix also specifies the versions of the cookbooks we already have installed on the chef server. The `Berksfile.lock` we had in the repo was specifying the lastest versions of the cookbooks because I didn't tell it otherwise :x

Note that I misunderstood how berkshelf works and didn't properly document how to use it. Basically, I confused how berkshelf works with how bundler works. When you install your deps, I assumed it would update the `Berkshelf.lock` file. Turns out, only a `berks install` with no lock file, and `berks update` actually write that file. It looks like there are fixes in the upcoming 2.0 release of berkshelf that will make it act more like bundler, and then I won't feel so bad about having the lockfile in the repo.

So, for now, whenever you add a cookbook and do `berks install`, make sure to go ahead and do a `berks update` as well. I updated the README to reflect this.

I also snuck the chef-zero gem into our bundle. This came in really handy when testing this stuff.