Fix some issues with ansible install procedure

 - Fixed Ubuntu installs of ansible via PPA (Tested on 10.04 (lucid), 12.04 (precise), 13.10 (saucy), 14.04 (trusty))

 - Fix errors about ansible runtime-dependency: python-selinux/libselinux-python (ansible requires this on the host where it is run.. so we install it inside vagrant box)
Merge pull request #6 from trinitronx/fix-some-ansible-install-issues

Fix some issues with ansible install procedure