Add support for multi-master test; others

Many updates in this commit (whoops)

- Add support for testing multi-masters
  - Adds a 'puppetmaster1' instance
  - Adds an 'haproxy' instance with a profile
  - Update README to reflect that
  - Stub in activemq brokers to site.pp for additional master
  - Add an 'mco' profile to sync mcollective certs to new masters

- Add comments to Puppetfile
  - Add haproxy module to Puppetfile
  - Bump r10k module version

- Shorten environment.conf's modulepath by using relative paths