Ensure /etc/docker/daemon.json
Ensure /etc/docker/daemon.json

A recent Centos docker packaging change removed the default
/etc/docker/daemon.json file. As such we need to create an empty
json file if none exists before running Augeas to configure
the settings.

Change-Id: Ibfe04b468639002f55da7bb65d2606f730c700b7
Closes-bug: #1684297

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo