Test oslo.db against all supported SA branches

Currently we test only the latest supported SA branch in the gate,
which means regressions for previous versions might be introduced.

Depends on I4128272ce15b9e576d7b97b1adab4d5027108c7c to be merged
to oslo.db first.

Change-Id: Ia09e0c13db20ab6974d5c72d3f13363193c56f4d

modules/openstack_project/files/jenkins_job_builder/config/projects.yaml

@@ -1017,12 +1017,16 @@
     node: 'bare-precise || bare-trusty'
     tarball-site: tarballs.openstack.org
     doc-publisher-site: docs.openstack.org
+    envlist:
+      - sqla_08
+      - sqla_09
 
     jobs:
       - python-jobs
       - openstack-publish-jobs
       - pypi-jobs
       - translation-jobs
+      - 'gate-{name}-tox-{envlist}'
 
 - project:
     name: oslo.i18n

modules/openstack_project/files/zuul/layout.yaml

@@ -737,6 +737,12 @@ jobs:
   - name: gate-tempest-dsvm-ceilometer-mongodb-full
     voting: false
 
+  # TODO(rpodolyaka): make voting when the jobs pass on all SA versions
+  - name: gate-oslo.db-tox-sqla_08
+    voting: false
+  - name: gate-oslo.db-tox-sqla_09
+    voting: false
+
 # The project list is grouped by type of project, and within each
 # group, projects are sorted (mostly) alphabetically.
 projects:
@@ -1931,6 +1937,8 @@ projects:
       - name: translation-jobs
     check:
       - check-devstack-dsvm-cells
+      - gate-oslo.db-tox-sqla_08
+      - gate-oslo.db-tox-sqla_09
     gate:
       - gate-devstack-dsvm-cells
     experimental-tripleo: