neutron: Change release model for Octavia, OVN, and NSX

Update the release model for networking-ovn, octavia, and vmware-nsx
to be "release:independent." These projects have not released anything
during Mitaka yet, so the release tag of "cycle-with-milestones" is no
longer accurate. We can change this tag back to "cycle-with-milestones"
during Newton if the teams desire.

Change-Id: Ib50d6ba766075c64ccd13824096278b165223a05
Signed-off-by: Kyle Mestery <mestery@mestery.com>

reference/projects.yaml

@@ -2143,7 +2143,7 @@ neutron:
       repos:
         - openstack/networking-ovn
       tags:
-        - release:cycle-with-milestones
+        - release:independent
     networking-plumgrid:
       repos:
         - openstack/networking-plumgrid
@@ -2201,7 +2201,7 @@ neutron:
       repos:
         - openstack/octavia
       tags:
-        - release:cycle-with-milestones
+        - release:independent
         - release:has-stable-branches
     python-neutron-pd-driver:
       repos:
@@ -2221,7 +2221,7 @@ neutron:
       repos:
         - openstack/vmware-nsx
       tags:
-        - release:cycle-with-milestones
+        - release:independent
         - release:has-stable-branches
 
 nova: