Working on my system
Properly configure WS_HOME variable when always_set_home or env_reset is configured in sudoers, as is the case for CentOS 6
Change '== "ubuntu"' to '!= "mac_os_x"' to enable support for CentOS
Merge pull request #197 from webcoyote/centos

Fixes for CentOS
Merge branch 'master' of https://github.com/pivotal/pivotal_workstation into issue/fix-bash-it-custom-plugins