Use a tox environment to update the release files

HOWTORELEASE.rst

@@ -24,13 +24,13 @@ To publish a new release ``X.Y.Z``, the steps are as follows:
 
 #. Create a new branch named ``release-X.Y.Z`` from the latest ``master``.
 
-#. Install ``pytest-xdist`` and dev requirements in a virtualenv::
+#. Install ``tox`` in a virtualenv::
 
-    $ pip install -e . -U -r dev-requirements.txt
+    $ pip install tox
 
-#. Update ``CHANGELOG.rst`` file by running::
+#. Update the necessary files with::
 
-    $ towncrier --version X.Y.Z --yes
+    $ tox -e release -- X.Y.Z
 
 #. Commit and push the branch for review.
 

dev-requirements.txt

@@ -1 +0,0 @@
-towncrier

tox.ini

@@ -40,7 +40,18 @@ deps = readme
 skip_install = true
 commands = python setup.py check -r -s
 
+[testenv:release]
+changedir=
+decription = do a release, required posarg of the version number
+basepython = python3.6
+skipsdist = True
+usedevelop = True
+passenv = *
+deps =
+    towncrier
+commands =
+    towncrier --version {posargs} --yes
 
 [pytest]
 addopts = -rsfxX
-;; hello
+