Without adding the user to the group you're going to hit nasty TLS errors. Figured I'd save the next guy the hassle.
Problem more accurately described here:
https://github.com/docker/docker/issues/5314
Signed-off-by: Jason Divock <jdivock@box.com>
Upstream-commit: 25d07511ed63959777ab1d0bee9f8e5f79382318
Component: engine