[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

Change-Id: Ia01dfa4bc5d7224bb0f753116cd23bdcc22df146
Sem-Ver: api-break

.zuul.yaml

@@ -1,10 +1,8 @@
 - project:
     templates:
       - check-requirements
-      - lib-forward-testing
       - lib-forward-testing-python3
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti

doc/requirements.txt

@@ -3,7 +3,6 @@
 # process, which may cause wedges in the gate later.
 
 openstackdocstheme>=1.20.0 # Apache-2.0
-sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4' # BSD
+sphinx>=1.8.0,!=2.1.0 # BSD
 reno>=2.5.0 # Apache-2.0
 sphinxcontrib-apidoc>=0.2.0  # BSD

lower-constraints.txt

@@ -6,12 +6,10 @@ cffi==1.7.0
 debtcollector==1.2.0
 docutils==0.11
 dulwich==0.15.0
-enum34==1.0.4;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 eventlet==0.18.2
 extras==1.0.0
 fixtures==3.0.0
 flake8==2.5.5
-futures==3.1.1;python_version=='2.7' or python_version=='2.6' # PSF
 gitdb==0.6.4
 GitPython==1.0.1
 greenlet==0.4.10
@@ -24,7 +22,6 @@ linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
 mock==2.0.0
-monotonic==0.6
 mox3==0.20.0
 msgpack-python==0.4.0
 msgpack==0.5.0

releasenotes/notes/drop-python27-support-6da3028c1cf099eb.yaml

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

requirements.txt

@@ -6,9 +6,7 @@ oslo.log>=3.36.0 # Apache-2.0
 oslo.i18n>=3.15.3 # Apache-2.0
 oslo.config>=5.2.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
-enum34>=1.0.4;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 cffi>=1.7.0 # MIT
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
 greenlet>=0.4.10 # MIT
 msgpack>=0.5.0 # Apache-2.0
-futures>=3.1.1;python_version=='2.7' or python_version=='2.6' # PSF

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/oslo.privsep/latest/
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,29 +14,16 @@ 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 =
     oslo_privsep
 
-[pbr]
-autodoc_index_modules = True
-api_doc_dir = reference/api
-autodoc_exclude_modules =
-  oslo_privsep.tests.*
-  oslo_privsep._*
-
-[build_sphinx]
-source-dir = doc/source
-build-dir = doc/build
-all_files = 1
-warning-is-error = 1
-
 [entry_points]
 console_scripts =
     privsep-helper = oslo_privsep.daemon:helper_main
@@ -43,9 +31,6 @@ console_scripts =
 oslo.config.opts =
     oslo.privsep = oslo_privsep.priv_context:_list_opts
 
-[upload_sphinx]
-upload-dir = doc/build/html
-
 [compile_catalog]
 directory = oslo.privsep/locale
 domain = oslo_privsep
@@ -59,6 +44,3 @@ input_file = oslo_privsep/locale/oslo_privsep.pot
 keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
 output_file = oslo_privsep/locale/oslo_privsep.pot
-
-[wheel]
-universal = true

setup.py

@@ -16,14 +16,6 @@
 # THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
-# In python < 2.7.4, a lazy loading of package `pbr` will break
-# setuptools if some other modules registered functions in `atexit`.
-# solution from: http://bugs.python.org/issue15881#msg170215
-try:
-    import multiprocessing  # noqa
-except ImportError:
-    pass
-
 setuptools.setup(
     setup_requires=['pbr>=2.0.0'],
     pbr=True)

tox.ini

@@ -1,7 +1,7 @@
 [tox]
-minversion = 3.1
-envlist = py27,py37,pypy,pep8
-ignore_basepython_conflict = True
+minversion = 3.1.1
+envlist = py37,pypy,pep8
+ignore_basepython_conflict = true
 
 [testenv]
 basepython = python3