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/releasenotes/notes/drop-py-2-7-b86d74653b14779b.yaml b/releasenotes/notes/drop-py-2-7-b86d74653b14779b.yaml
new file mode 100644
index 0000000..1ad8a34
--- /dev/null
+++ b/releasenotes/notes/drop-py-2-7-b86d74653b14779b.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. Last release of telemetry-tempest-plugin
+    to support py2.7 is OpenStack Train. The minimum version of Python now
+    supported by telemetry-tempest-plugin is Python 3.6.