cf8c2c21ac
The restriction is no longer necessary given changes at the runc layer related to mount options of the rootfs. Also cleaned up the docs on restrictions left for userns enabled mode. Re-enabled tests related to --read-only when testing a userns-enabled daemon in integration-cli. Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)