|Fixed test suite issues:
* Shell environment for test suite regression fixed.
* Vagrantfile referred to SDP rather than Helix Installer (old
Copy/Paste issue, harmless but wrong).
* Updated baseline Vagrant image for CentOS6 box.
* Fixed issue with setting hostname on CentOS6 by making hostname
a paramter to the bootstrap script, and adjusting the bootstrap
Along with this change, added missing hostmanager plugin on test