[ussuri][goal] Drop python 2.7 support and testing

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

monasca-persister 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://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html

Depends-On: https://review.opendev.org/#/c/693631/
Change-Id: I628603dadcaabbe24d4d166dfb47d4413c9dbaac

.zuul.yaml

@@ -3,22 +3,18 @@
       - check-requirements
       - openstack-cover-jobs
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - release-notes-jobs-python3
     check:
       jobs:
-        - monasca-tempest-python2-influxdb
         - monasca-tempest-python3-influxdb
-        - monasca-tempest-python2-cassandra
-        - monasca-tempest-python2-java-cassandra
+        - monasca-tempest-python3-cassandra
+        - monasca-tempest-python3-java-cassandra
         - docker-build-monasca-service
         - legacy-monasca-persister-maven-build
     gate:
       jobs:
-        - monasca-tempest-python2-influxdb
         - monasca-tempest-python3-influxdb
-        - monasca-tempest-python2-cassandra
         - legacy-monasca-persister-maven-build
     post:
       jobs:

README.rst

@@ -28,7 +28,7 @@ To run the unit tests use:
 
 ::
 
-   $ tox -e py27,py36
+   $ tox -e py36
 
 To start the persister run:
 

releasenotes/notes/drop-py-2-7-048b2fafecb6f6af.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. Last release of monasca-persister
+    to support python 2.7 is OpenStack Train. The minimum version of Python now
+    supported by monasca-persister is Python 3.6.

setup.cfg

@@ -8,8 +8,6 @@ classifier=
   License :: OSI Approved :: Apache Software License
   Topic :: System :: Monitoring
   Programming Language :: Python
-  Programming Language :: Python :: 2
-  Programming Language :: Python :: 2.7
   Programming Language :: Python :: 3
   Programming Language :: Python :: 3.6
   Programming Language :: Python :: 3.7

test-requirements.txt

@@ -12,7 +12,6 @@ docutils>=0.11 # OSI-Approved Open Source, Public Domain
 pycodestyle>=2.5.0 # MIT
 
 # release notes
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
 reno>=2.5.0 # Apache-2.0
 openstackdocstheme>=1.20.0 # Apache-2.0

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py37,pep8
+envlist = py37,pep8
 minversion = 2.1
 skipsdist = True