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

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

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

Cleanup setup.cfg as well.

Increase requests version in lower-constraints:
requests>=2.18.0 is needed by oslo.config, which leads to some other
updates...

Change-Id: I09f0da9a59952739dd1575200aa47cc12026264f

.zuul.yaml

@@ -60,7 +60,6 @@
     templates:
       - check-requirements
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti

doc/requirements.txt

@@ -1,5 +1,4 @@
-sphinx>=1.8.0,<2.0.0;python_version=='2.7'  # BSD
+sphinx>=1.8.0,!=2.1.0  # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4'  # BSD
 sphinxcontrib-svg2pdfconverter>=0.1.0 # BSD
 reno>=2.5.0 # Apache-2.0
 openstackdocstheme>=1.18.1 # Apache-2.0

lower-constraints.txt

@@ -17,7 +17,7 @@ flake8==2.5.5
 gitdb==0.6.4
 GitPython==1.0.1
 hacking==0.12.0
-idna==2.6
+idna==2.5
 imagesize==0.7.1
 iso8601==0.1.11
 Jinja2==2.10
@@ -55,7 +55,7 @@ python-mimeparse==1.6.0
 python-subunit==1.0.0
 pytz==2013.6
 PyYAML==3.12
-requests==2.14.2
+requests==2.18.0
 requestsexceptions==1.2.0
 rfc3986==0.3.1
 six==1.10.0

releasenotes/notes/drop-python-2-7-73d3113c69d724d6.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. The minimum version of Python now
+    supported by castellan is Python 3.6.

requirements.txt

@@ -13,4 +13,4 @@ oslo.log>=3.36.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
 stevedore>=1.20.0 # Apache-2.0
 keystoneauth1>=3.4.0 # Apache-2.0
-requests>=2.14.2,!=2.20.0 # Apache-2.0
+requests>=2.18.0,!=2.20.0 # Apache-2.0

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/castellan/latest/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,11 +14,11 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     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
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: Implementation :: CPython
 
 [files]
 packages =
@@ -35,15 +36,6 @@ castellan.drivers =
     barbican = castellan.key_manager.barbican_key_manager:BarbicanKeyManager
     vault = castellan.key_manager.vault_key_manager:VaultKeyManager
 
-[build_sphinx]
-source-dir = doc/source
-build-dir = doc/build
-all_files = 1
-warning-is-error = 1
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
 [compile_catalog]
 directory = castellan/locale
 domain = castellan
@@ -57,6 +49,3 @@ input_file = castellan/locale/castellan.pot
 keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
 output_file = castellan/locale/castellan.pot
-
-[wheel]
-universal = 1

tox.ini

@@ -1,11 +1,12 @@
 [tox]
-minversion = 2.0
+minversion = 3.1.1
-envlist = py27,py37,pep8
+envlist = py37,pep8
+ignore_basepython_conflict = True
 skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = pip install {opts} {packages}
+basepython = python3
 setenv =
    VIRTUAL_ENV={envdir}
    OS_TEST_PATH=./castellan/tests/unit
@@ -15,17 +16,12 @@ deps =
        -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
 
-[testenv:py27]
-basepython = python2.7
-
 [testenv:pep8]
-basepython = python3
 commands =
   flake8
   bandit -r castellan -x tests -s B105,B106,B107,B607
 
 [testenv:bandit]
-basepython = python3
 # This command runs the bandit security linter against the castellan
 # codebase minus the tests directory. Some tests are being excluded to
 # reduce the number of positives before a team inspection, and to ensure a
@@ -38,15 +34,12 @@ commands =
   bandit -r castellan -x tests -s B105,B106,B107,B607
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:debug]
-basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [testenv:cover]
-basepython = python3
 setenv =
     PYTHON=coverage run --source $project --parallel-mode
 commands =
@@ -60,7 +53,6 @@ commands =
 # This environment is called from CI scripts to test and publish
 # the main docs to https://docs.openstack.org/castellan
 description = Build main documentation
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands=
     rm -rf doc/build doc/build/doctrees
@@ -68,7 +60,6 @@ commands=
 whitelist_externals = rm
 
 [testenv:pdf-docs]
-basepython = python3
 deps = {[testenv:docs]deps}
 envdir = {toxworkdir}/docs
 whitelist_externals =
@@ -80,7 +71,6 @@ commands =
   make -C doc/build/pdf
 
 [testenv:releasenotes]
-basepython = python3
 deps = {[testenv:docs]deps}
 envdir = {toxworkdir}/docs
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
@@ -104,7 +94,6 @@ commands =
     {toxinidir}/tools/setup-vault-env.sh pifpaf -e VAULT_TEST run vault -- stestr run --slowest {posargs}
 
 [testenv:genconfig]
-basepython = python3
 commands =
     oslo-config-generator --config-file=etc/castellan/functional-config-generator.conf
     oslo-config-generator --config-file=etc/castellan/sample-config-generator.conf
@@ -120,14 +109,12 @@ enable-extensions = H106,H203
 import_exceptions = castellan.i18n
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 
 [testenv:bindep]
-basepython = python3
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system
 # dependencies are missing! This also means that bindep must be installed