Use Ohai root_group attribute, rather than swapping between root and wheel if platform is mac_os_x.
Use Ohai root_group attribute, rather than swapping between root and wheel if platform is mac_os_x.

Signed-off-by: Christopher Williams <492258988043caf751f81dafaf9d54b5c643bcd3@gmail.com>

chef-cookbooks/ark,chef-cookbooks/ark,Sauraus/ark,Sauraus/ark