Add docs on the release process

Author: nicoddemus

HOWTORELEASE.rst

@@ -0,0 +1,37 @@
+=================
+Releasing execnet
+=================
+
+This document describes the steps to make a new ``execnet`` release.
+
+Version
+-------
+
+``master`` should always be green and a potential release candidate. ``execnet`` follows
+semantic versioning, so given that the current version is ``X.Y.Z``, to find the next version number
+one needs to look at the ``CHANGELOG.rst`` file:
+
+- If there any new feature, then we must make a new **minor** release: next
+  release will be ``X.Y+1.0``.
+
+- Otherwise it is just a **bug fix** release: ``X.Y.Z+1``.
+
+
+Steps
+-----
+
+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``.
+
+#. Update the ``CHANGELOG.rst`` file with the new release information.
+
+#. Commit and push the branch for review.
+
+#. Once PR is **green** and **approved**, create and push a tag::
+
+    $ export VERSION=X.Y.Z
+    $ git tag v$VERSION release-$VERSION
+    $ git push [email protected]:pytest-dev/execnet.git v$VERSION
+
+That will build the package and publish it on ``PyPI`` automatically.