v0.6.0

FEATURES:

• Add ability to install Chef before provisioning. This allows you to, for
  example, provision bare servers that have nothing installed but the base
  operating system. For this, use the new -i option (or --install-chef).
• Add support for Berkshelf v3 in addition to v2. (Thanks to @arosenhagen for
  the original pull request!)
• Re-add long option names like --host and --json-attributes. Those were
  removed when porting chef-runner to Go (v0.2.0).
• Re-add ability to install chef-runner via Homebrew.

IMPROVEMENTS:

• Add Quick Start guide to README.
• Only prepend bundle exec to Ruby commands if Bundler is actually installed.
  A Gemfile alone is no longer enough.
• Add basic Godoc documentation to all parts of the source code. As a result,
  golint no longer reports any coding style issues.
• Run golint style checks on Travis CI.

BREAKING CHANGES:

• Change default output format of Chef from null to doc. The former is the
  default used by Vagrant, while the latter is the actual default of Chef Solo.