Add --system to useradd commands
Merge pull request #28 from Metaswitch/usergroup

[Reviewer: Andy] Add --system to useradd commands
Updated debian/copyright file
Merge pull request #29 from Metaswitch/deb_copyright

[Reviewer: Matt] Updated debian/copyright file
Merge remote-tracking branch 'remotes/origin/dev' into new_homestead_api