Updated Ironic Microversions Spec to fix minor errors.
Updated Ironic Microversions Spec to fix minor errors.

Updated Ironic Microversions Spec to fix references of Nova's
microversioning spec URL and Use Case 7A, and a few typos.

Change-Id: I76f0129fa09a28a888aa90ffce3324b4021e113a

NaohiroTamura/ironic-specs,naterh/ironic-specs,bcornec/ironic-specs,openstack/ironic-specs