Release v2.1.1

• updating attributes/default.rb, and .kitchen.yml to match default.rb
• removing marker
• updating to chefdk - 1.2.22
• updating for kitchen-dokken support and pinning to machine_tag >= 2.0.4
• updating to fix issue [#45][], changing settings on the socket, and sudo from the collectd script
• support for ubuntu 1604
• cleaned up Gemfile
• removed coveralls support
• updated chefspec to ubuntu 1404
• removed .ruby-version because we use chef-dk