Some configuration options for tempest scenario

These configuration options are connected with
baremetal ops scenario. This scenario is intended
to testing baremetal provisioning. There are two
other pull requests into devstack-gate and into
tempest.

Change-Id: I77f3a6a76994251b039372a12449f2d88d3f75ab
Add ssh-keygen

Change-Id: I911f842f6be11adaae260e3a3aeaa0c10004b77a
Finish ssh magic for ironic

Change-Id: I496386e0ad7dd1497ec53f99d2e6b90cd1f7dff2