Bug 1388013 - Support running |mach python-test| against Python 3 using pipenv; r=ahal

This patch allows executing |mach python-test| against Python 3 by specifying the optional |--three| command line option. When this option is present, pipenv will be used to manage a virtual environment using Python 3 and attempt to run the tests. When it is not present, pipenv will not be used, and everything will work as it did before this patch.

My original plan was to use pipenv regardless of the target version of Python, however I encountered several issues running some of the tests against our Python packages. Once all tests have been patched to run against Python 3, then we should be able to use pipenv when running them against Python 2.

Note that this patch allows tests to run against Python 3, but there are plenty of issues preventing them from passing. With this patch in place we can start to add Python 3 support to our packages and have the tests running in CI to ensure we don't regress back to just supporting Python 2.

MozReview-Commit-ID: BuU5gZK83hL


IHG: changed taskcluster/ci/source-test/python.yml

python/mozversioncontrol/setup.py

@@ -0,0 +1,27 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import
+
+from setuptools import setup, find_packages
+
+VERSION = '0.1'
+
+setup(
+    author='Mozilla Foundation',
+    author_email='Mozilla Release Engineering',
+    name='mozversioncontrol',
+    description='Mozilla version control functionality',
+    license='MPL 2.0',
+    packages=find_packages(),
+    version=VERSION,
+    classifiers=[
+        'Development Status :: 3 - Alpha',
+        'Topic :: Software Development :: Build Tools',
+        'License :: OSI Approved :: Mozilla Public License 2.0 (MPL 2.0)',
+        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: Implementation :: CPython',
+    ],
+    keywords='mozilla',
+)