Update CONTRIBUTING.md to discuss Chef Zero
Move gems to gemspec
Start Chef Zero at suite, not before each run
Only set the path option if it existed when parsing a legacy lockfile

- See #529
Add shared knife.rb and testing pems
Switch to new Chef Zero API
Use stock knife.rb in tests
Revert "Move gems to gemspec"

This reverts commit d21e89573fe59dfbfb9193cba9bf7dfdfe73f93a.
Bump CZ dependency
Merge pull request #546 from sethvargo/chef_zero_and_specs

Fix CZ on master
Add require 'kitchen' for InitGenerator
Only require the init generator from test-kitchen
Require kitchen generators in Berkshelf
No need to require kitchen generator here again
Stub Kitchen in CookbookGeneratorSpec
Stub Kitchen in InitGeneratorSpec
Skip test kitchen in the git cookbook generation as well
Automatically start Chef Zero in cukes
Force newline characters for #say
Only set the path option if it existed when parsing a legacy lockfile

- See #529