[all][release] Proposed release schedule for Ussuri

Hey everyone, Now that we have a date for the next event [0], it might be a good time to finalize the release cycle schedule for the Ussuri release. I have put up a proposal for the schedule here: https://review.opendev.org/#/c/679822/ Please take a look and give any feedback if you see any issues with where the milestone dates align with any major holidays or other external factors that we should consider. For your viewing convenience, here is the rendered output from the docs job: https://openstack.fortnebula.com:13808/v1/AUTH_e8fd161dc34c421a979a9e6421f82... Thanks! Sean [0] http://lists.openstack.org/pipermail/foundation/2019-September/002794.html