Updated openstack/openstack
Project: openstack/cliff  42675b2d7ad93f4bba9c4216874c68b8e5834147

Add release notes for 1.7.0

Add release notes for recent changes and update the formatting of older
release notes for consistency.

Change-Id: I3992b0c198eac41b2acf37d73e6642f47aeb5330