docs: link to PyPI release, not GitHub archive URL.

Now download counts are visible via PSF BigQuery.

docs/ansible.rst

@@ -60,13 +60,13 @@ Installation
 1. Thoroughly review the :ref:`noteworthy_differences` and :ref:`changelog`.
 2. Verify Ansible 2.3-2.5 and Python 2.6, 2.7 or 3.6 are listed in ``ansible
    --version`` output.
-3. Download and extract https://github.com/dw/mitogen/archive/stable.zip
+3. Download and extract |mitogen_url| from PyPI.
 4. Modify ``ansible.cfg``:
 
-   .. code-block:: dosini
+   .. parsed-literal::
 
         [defaults]
-        strategy_plugins = /path/to/mitogen-master/ansible_mitogen/plugins/strategy
+        strategy_plugins = /path/to/mitogen-|mitogen_version|/ansible_mitogen/plugins/strategy
         strategy = mitogen_linear
 
    The ``strategy`` key is optional. If omitted, the

docs/conf.py

@@ -2,15 +2,8 @@ import os
 import sys
 
 sys.path.append('..')
-
-def grep_version():
-    path = os.path.join(os.path.dirname(__file__), '../mitogen/__init__.py')
-    with open(path) as fp:
-        for line in fp:
-            if line.startswith('__version__'):
-                _, _, s = line.partition('=')
-                return '.'.join(map(str, eval(s)))
-
+import mitogen
+VERSION = '%s.%s.%s' % mitogen.__version__
 
 author = u'David Wilson'
 copyright = u'2018, David Wilson'
@@ -31,8 +24,16 @@ language = None
 master_doc = 'toc'
 project = u'Mitogen'
 pygments_style = 'sphinx'
-release = grep_version()
+release = VERSION
 source_suffix = '.rst'
 templates_path = ['_templates']
 todo_include_todos = False
-version = grep_version()
+version = VERSION
+
+rst_epilog = """
+
+.. |mitogen_version| replace:: %(VERSION)s
+
+.. |mitogen_url| replace:: `mitogen-%(VERSION)s.tar.gz <https://files.pythonhosted.org/packages/source/m/mitogen/mitogen-%(VERSION)s.tar.gz>`__
+
+""" % locals()