Update python testing as per zed cycle teting runtime

In Zed cycle, we have dropped the python 3.6/3.7[1] testing
and its support. Add release notes, move py36 jobs to py38|9,
and update the python classifier for the same.

[1] https://governance.openstack.org/tc/reference/runtimes/zed.html

Change-Id: Ibeee0b16ee1ea95f05127563a9cb08ffd0f04e2b

.gitreview

@@ -2,4 +2,3 @@
 host=review.opendev.org
 port=29418
 project=openstack/python-neutronclient.git
-defaultbranch=stable/yoga

.zuul.yaml

@@ -1,8 +1,7 @@
 - project:
     templates:
       - openstack-cover-jobs
-      - openstack-lower-constraints-jobs
-      - openstack-python3-yoga-jobs
+      - openstack-python3-zed-jobs
       - publish-openstack-docs-pti
       - check-requirements
       - lib-forward-testing-python3

lower-constraints.txt

@@ -1,111 +0,0 @@
-alabaster==0.7.10
-amqp==2.1.1
-appdirs==1.3.0
-asn1crypto==0.23.0
-Babel==2.3.4
-cachetools==2.0.0
-cffi==1.14.0
-cliff==3.4.0
-cmd2==0.8.0
-contextlib2==0.4.0
-coverage==4.0
-cryptography==2.7
-debtcollector==1.2.0
-decorator==4.1.0
-deprecation==1.0
-docutils==0.11
-dogpile.cache==0.6.5
-dulwich==0.15.0
-eventlet==0.18.2
-extras==1.0.0
-fasteners==0.7.0
-fixtures==3.0.0
-flake8-import-order==0.12
-flake8==3.6.0
-future==0.16.0
-futurist==1.2.0
-greenlet==0.4.10
-hacking==3.0.1
-idna==2.6
-imagesize==0.7.1
-iso8601==0.1.11
-Jinja2==2.10
-jmespath==0.9.0
-jsonpatch==1.16
-jsonpointer==1.13
-jsonschema==2.6.0
-keystoneauth1==3.8.0
-kombu==4.0.0
-linecache2==1.0.0
-MarkupSafe==1.0
-mccabe==0.6.0
-monotonic==0.6
-msgpack-python==0.4.0
-munch==2.1.0
-netaddr==0.7.18
-netifaces==0.10.4
-openstacksdk==0.15.0
-os-client-config==1.28.0
-os-service-types==1.2.0
-osc-lib==1.12.0
-oslo.concurrency==3.26.0
-oslo.config==5.2.0
-oslo.context==2.19.2
-oslo.i18n==3.15.3
-oslo.log==3.36.0
-oslo.messaging==5.29.0
-oslo.middleware==3.31.0
-oslo.serialization==2.18.0
-oslo.service==1.24.0
-oslo.utils==3.33.0
-oslotest==3.2.0
-osprofiler==2.3.0
-paramiko==2.0.0
-Paste==2.0.2
-PasteDeploy==1.5.0
-pbr==2.0.0
-pika-pool==0.1.3
-pika==0.10.0
-positional==1.2.1
-prettytable==0.7.2
-pyasn1==0.1.8
-pycodestyle==2.4.0
-pycparser==2.18
-pyflakes==2.0.0
-Pygments==2.2.0
-pyinotify==0.9.6
-pyOpenSSL==17.1.0
-pyparsing==2.1.0
-pyperclip==1.5.27
-python-cinderclient==3.3.0
-python-dateutil==2.5.3
-python-glanceclient==2.8.0
-python-keystoneclient==3.8.0
-python-mimeparse==1.6.0
-python-novaclient==9.1.0
-python-openstackclient==3.12.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==5.3.1
-repoze.lru==0.7
-requests-mock==1.2.0
-requests==2.14.2
-requestsexceptions==1.2.0
-rfc3986==0.3.1
-Routes==2.3.1
-simplejson==3.5.1
-snowballstemmer==1.2.1
-statsd==3.2.1
-stestr==2.0.0
-stevedore==2.0.1
-tempest==17.1.0
-tenacity==3.2.1
-testscenarios==0.4
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-urllib3==1.21.1
-vine==1.1.4
-warlock==1.2.0
-WebOb==1.7.1
-wrapt==1.7.0

releasenotes/notes/drop-python-3-6-and-3-7-73767fa0bbe89a6e.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Python 3.6 & 3.7 support has been dropped. The minimum version of Python now
+    supported is Python 3.8.

releasenotes/source/index.rst

@@ -6,6 +6,7 @@
    :maxdepth: 1
 
    unreleased
+   yoga
    xena
    wallaby
    victoria

releasenotes/source/yoga.rst

@@ -0,0 +1,6 @@
+=========================
+Yoga Series Release Notes
+=========================
+
+.. release-notes::
+   :branch: stable/yoga

requirements.txt

@@ -1,3 +1,7 @@
+# Requirements lower bounds listed here are our best effort to keep them up to
+# date but we do not test them so no guarantee of having them all correct. If
+# you find any incorrect lower bounds, let us know or propose a fix.
+
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.

setup.cfg

@@ -6,7 +6,7 @@ description_file =
 author = OpenStack Networking Project
 author_email = openstack-discuss@lists.openstack.org
 home_page = https://docs.openstack.org/python-neutronclient/latest/
-python_requires = >=3.6
+python_requires = >=3.8
 classifier =
     Environment :: OpenStack
     Intended Audience :: Developers
@@ -18,8 +18,6 @@ classifier =
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.6
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
 

tox.ini

@@ -13,7 +13,7 @@ setenv = VIRTUAL_ENV={envdir}
          PYTHONWARNINGS=default::DeprecationWarning
 usedevelop = True
 install_command = pip install {opts} {packages}
-deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/yoga}
+deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 # Delete bytecodes from normal directories before running tests.
@@ -52,7 +52,7 @@ commands =
 
 [testenv:docs]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/yoga}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
@@ -67,7 +67,7 @@ commands =
 
 [testenv:releasenotes]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/yoga}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
@@ -86,9 +86,3 @@ enable-extensions=H904
 #       components.
 deps = -r{toxinidir}/test-requirements.txt
 commands = bandit -r neutronclient -x tests -n5 -s B303,B105
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt