Deprecation plan for nova-baremetal

This spec outlines the process for upgrading from nova-baremetal to
Ironic, and descibes the changes in Nova which will be required prior
to deleting the nova-baremetal code from the Nova tree.

blueprint deprecate-baremetal-driver

Change-Id: I2a9e6ca2f19d5b0f80954cdec45a9eca17960fa1
Merge "Deprecation plan for nova-baremetal"