Install OSC during quickstart
Install OSC during quickstart

The quickstart doc was missing the step of installing
python-openstackclient which has become necessary to provide
the `openstack` command. This was not required when the doc
was originally written as we then used the `ironic` command.

Change-Id: Ia529a37730b1df6c6574e10d97a25bc2e547647a

openstack/ironic,openstack/ironic