Release 2.2.0
A bunch of small changes that collectively push this to a feature release:
- add stahnma-epel dependency
- use nobody:nogroup permissions for Ubuntu upstart script
- parameterize $statsd::config::configfile
- update Travis CI config
- fix linting, style warnings
- update Gemfile, Puppetfile, License, Readme, Rakefile
- split Vagrant config for CentOS and Ubuntu -- use latest Puppet Labs boxes for both