📦 Substitute pbr with setuptools-scm

Also:
* 🎨 include a shim to simulate setuptools' ability to read data from
``setup.cfg`` under ancient envs.
* ⬆️ BSpecify project stability in metadata properly
* ⬆️ Bump required tox to v3.8.4
* 🎨 Retrieve Molecule version using pkg_resources
* 🐛 Whitelist find in tox in build-dists
* 🎨 Enable isolated build in tox
* 🔥 Drop Ansible 2.4 factor ref from tox
* ⬆️ Bump setuptools req to v41.0.0
* 🎨 Wire up tox build-dists env into Travis CI

Co-Authored-By: webknjaz <wk.cvs.github@sydorenko.org.ua>

.git_archival.txt

@@ -0,0 +1 @@
+ref-names: $Format:%D$

.gitattributes

@@ -0,0 +1,202 @@
+# Force LF line endings for text files
+* text=auto eol=lf
+
+## SOURCE CODE
+*.bat      text eol=crlf
+*.coffee   text
+*.css      text
+*.htm      text diff=html
+*.html     text diff=html
+*.inc      text
+*.ini      text
+*.js       text
+*.json     text
+*.jsx      text
+*.less     text
+*.od       text
+*.onlydata text
+*.php      text diff=php
+*.pl       text
+*.pxd      text diff=python
+*.py       text diff=python
+*.py3      text diff=python
+*.pyw      text diff=python
+*.pyx      text diff=python
+*.rb       text diff=ruby
+*.sass     text
+*.scm      text
+*.scss     text
+*.sh       text eol=lf
+*.sql      text
+*.styl     text
+*.tag      text
+*.ts       text
+*.tsx      text
+*.vue      text
+*.xml      text
+*.xhtml    text diff=html
+
+## DOCKER
+*.dockerignore    text
+Dockerfile    text
+
+## DOCUMENTATION
+*.ipynb      text
+*.markdown   text
+*.md         text
+*.mdwn       text
+*.mdown      text
+*.mkd        text
+*.mkdn       text
+*.mdtxt      text
+*.mdtext     text
+*.txt        text
+AUTHORS      text
+CHANGELOG    text
+CHANGES      text
+CONTRIBUTING text
+COPYING      text
+copyright    text
+*COPYRIGHT*  text
+INSTALL      text
+license      text
+LICENSE      text
+NEWS         text
+readme       text
+*README*     text
+TODO         text
+
+## TEMPLATES
+*.dot        text
+*.ejs        text
+*.haml       text
+*.handlebars text
+*.hbs        text
+*.hbt        text
+*.jade       text
+*.latte      text
+*.mustache   text
+*.njk        text
+*.phtml      text
+*.tmpl       text
+*.tpl        text
+*.twig       text
+
+## LINTERS
+.csslintrc    text
+.eslintrc     text
+.htmlhintrc   text
+.jscsrc       text
+.jshintrc     text
+.jshintignore text
+.stylelintrc  text
+
+## CONFIGS
+*.bowerrc      text
+*.cnf          text
+*.conf         text
+*.config       text
+.babelrc       text
+.browserslistrc    text
+.editorconfig  text
+.env           text
+.gitattributes text
+.gitconfig     text
+.htaccess      text
+*.lock         text
+*.npmignore    text
+*.yaml         text
+*.yml          text
+browserslist   text
+Makefile       text
+makefile       text
+
+## HEROKU
+Procfile    text
+.slugignore text
+
+## GRAPHICS
+*.ai   binary
+*.bmp  binary
+*.eps  binary
+*.gif  binary
+*.ico  binary
+*.jng  binary
+*.jp2  binary
+*.jpg  binary
+*.jpeg binary
+*.jpx  binary
+*.jxr  binary
+*.pdf  binary
+*.png  binary
+*.psb  binary
+*.psd  binary
+*.svg  text
+*.svgz binary
+*.tif  binary
+*.tiff binary
+*.wbmp binary
+*.webp binary
+
+## AUDIO
+*.kar  binary
+*.m4a  binary
+*.mid  binary
+*.midi binary
+*.mp3  binary
+*.ogg  binary
+*.ra   binary
+
+## VIDEO
+*.3gpp binary
+*.3gp  binary
+*.as   binary
+*.asf  binary
+*.asx  binary
+*.fla  binary
+*.flv  binary
+*.m4v  binary
+*.mng  binary
+*.mov  binary
+*.mp4  binary
+*.mpeg binary
+*.mpg  binary
+*.ogv  binary
+*.swc  binary
+*.swf  binary
+*.webm binary
+
+## ARCHIVES
+*.7z  binary
+*.gz  binary
+*.jar binary
+*.rar binary
+*.tar binary
+*.zip binary
+
+## FONTS
+*.ttf   binary
+*.eot   binary
+*.otf   binary
+*.woff  binary
+*.woff2 binary
+
+## EXECUTABLES
+*.exe binary
+*.pyc binary
+
+# Binary files
+# ============
+*.db  binary
+*.p   binary
+*.pkl binary
+*.pyd binary
+*.pyo binary
+
+# Note: .db, .p, and .pkl files are associated
+# with the python modules ``pickle``, ``dbm.*``,
+# ``shelve``, ``marshal``, ``anydbm``, & ``bsddb``
+# (among others).
+
+# Needed for setuptools-scm-git-archive:
+.git_archival.txt  export-subst

.travis.yml

@@ -429,7 +429,9 @@ jobs:
     name: Publishing current Git tagged version of dist to PyPI
     if: repo == "ansible/molecule" AND tag IS present
     env:
-      TOXENV: metadata-validation
+      TOXENV: metadata-validation,build-dists
+    before_deploy:
+    - echo > setup.py
     deploy: &deploy-step
       provider: pypi
       user: ansible-molecule

molecule/__init__.py

@@ -1,3 +1,4 @@
+#  Copyright (c) 2019 Red Hat, Inc.
 #  Copyright (c) 2015-2018 Cisco Systems, Inc.
 #
 #  Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -17,8 +18,13 @@
 #  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 #  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 #  DEALINGS IN THE SOFTWARE.
+"""Molecule version information."""
 
-import pbr.version
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
 
-version_info = pbr.version.VersionInfo('molecule')  # noqa
-__version__ = version_info.release_string()
+try:
+    import pkg_resources
+    __version__ = pkg_resources.get_distribution('molecule').version
+except Exception:
+    __version__ = 'unknown'

pyproject.toml

@@ -0,0 +1,8 @@
+[build-system]
+requires = [
+  "setuptools >= 41.0.0",
+  "setuptools_scm >= 1.15.0",
+  "setuptools_scm_git_archive >= 1.0",
+  "wheel",
+]
+build-backend = "setuptools.build_meta"