Drop python 2.7 support and testing

OpenStack is dropping the py2.7 support in ussuri cycle.

telemetry-tempest-plugin is ready with python 3 and ok to drop the
python 2.7 support.

Complete discussion & schedule can be found in
- http://lists.openstack.org/pipermail/openstack-discuss/2019-October/010142.html
- https://etherpad.openstack.org/p/drop-python2-support

Ussuri Communtiy-wide goal - https://review.opendev.org/#/c/691178/

Change-Id: I72abc58ee67cf0594faa07e0f89b52f1c9cc6c2f
diff --git a/.zuul.yaml b/.zuul.yaml
index f765840..2c9e423 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -1,5 +1,8 @@
 - job:
     name: telemetry-tempest-base
+    description: |
+      This job is for stable branch prior to Ussuri for testing
+      on py2.
     parent: devstack-tempest
     irrelevant-files:
       - ^(test-|)requirements.txt$
@@ -8,6 +11,54 @@
       - ^.*\.rst$
       - ^releasenotes/.*$
     timeout: 7800
+    required-projects:
+      - openstack/devstack-gate
+      - openstack/panko
+      - openstack/aodh
+      - openstack/ceilometer
+      - openstack/telemetry-tempest-plugin
+      - openstack/heat-tempest-plugin
+      - openstack/heat
+      - openstack/dib-utils
+      - openstack/diskimage-builder
+      - openstack/tempest
+    vars:
+      devstack_plugins:
+        heat: https://opendev.org/openstack/heat
+        ceilometer: https://opendev.org/openstack/ceilometer
+        aodh: https://opendev.org/openstack/aodh
+        panko: https://opendev.org/openstack/panko
+      devstack_services:
+        tempest: true
+        tls-proxy: false
+      devstack_localrc:
+        TEMPEST_PLUGINS: '"/opt/stack/telemetry-tempest-plugin /opt/stack/heat-tempest-plugin"'
+        GNOCCHI_ARCHIVE_POLICY_TEMPEST: "ceilometer-high-rate"
+        CEILOMETER_BACKEND: "gnocchi"
+        CEILOMETER_PIPELINE_INTERVAL: 15
+        USE_PYTHON3: False
+      tempest_test_regex: telemetry_tempest_plugin
+      tox_envlist: all
+    branches:
+      - stable/ocata
+      - stable/pike
+      - stable/queens
+      - stable/rocky
+      - stable/stein
+      - stable/train
+
+- job:
+    name: telemetry-tempest-base
+    parent: devstack-tempest
+    description: |
+      This job is for testing on py3 which is Ussuri onwards.
+    irrelevant-files:
+      - ^(test-|)requirements.txt$
+      - ^setup.cfg$
+      - ^doc/.*$
+      - ^.*\.rst$
+      - ^releasenotes/.*$
+    timeout: 7800
     required-projects: &base_required_projects
       - openstack/devstack-gate
       - openstack/panko