[Stable only] Drop *-master jobs

These jobs are used to test neutron against current master branches of
external projects (ryu).

Stable branches are not expected to run with this setup so we can drop
the jobs there (especially as some of these jobs are periodic ones).

Conflicts:
	.zuul.yaml

This is adapted to the older single .zuul.yaml file layout

Change-Id: I2b1f4c4e951b691fb0c66119699b26540b0babd8
(cherry picked from commit 21719a875d)
(cherry picked from commit da0bad4acc)

.zuul.yaml

@@ -52,7 +52,6 @@
       jobs:
         - neutron-functional
         - neutron-tempest-postgres-full
-        - neutron-tempest-with-ryu-master
     experimental:
       jobs:
         - neutron-functional-python35
@@ -135,17 +134,6 @@
               - ^setup.cfg$
               - ^tools/.*$
               - ^tox.ini$
-        - legacy-tempest-dsvm-neutron-with-ryu-master:
-            irrelevant-files:
-              - ^(test-|)requirements.txt$
-              - ^.*\.rst$
-              - ^doc/.*$
-              - ^neutron/locale/.*$
-              - ^neutron/tests/unit/.*$
-              - ^releasenotes/.*$
-              - ^setup.cfg$
-              - ^tools/.*$
-              - ^tox.ini$
     post:
       jobs:
         - openstack-tox-cover
@@ -427,17 +415,6 @@
       - openstack/neutron
       - openstack/tempest
 
-- job:
-    name: neutron-tempest-with-ryu-master
-    parent: legacy-dsvm-base
-    run: playbooks/legacy/neutron-tempest-with-ryu-master/run.yaml
-    post-run: playbooks/legacy/neutron-tempest-with-ryu-master/post.yaml
-    timeout: 7800
-    required-projects:
-      - openstack/devstack-gate
-      - openstack/neutron
-      - openstack/tempest
-
 - job:
     name: neutron-fullstack-with-uwsgi
     parent: legacy-dsvm-base