Reminder for OSX users not to use SUDO

Useful for those who haven't made it to the examples page yet. https://github.com/chadoh/docker/commit/dad4a998dc716e506c874ce0e792989b9df28748

Docker-DCO-1.1-Signed-off-by: No Ducks <onemannoducks@gmail.com> (github: noducks)
Merge pull request #4814 from noducks/master

Reminder for OSX users not to use SUDO