Add release instructions

Author: mwcraig

RELEASE.md

@@ -0,0 +1,41 @@
+# How to do a vpython release
+
+There are two things that need to be released:
+
++ The Python package `vpython-jupyter`
++ The JupyterLab extension called `vpython`
+
+## Releasing the Python package
+
+Versions for the Python package are generated using
+[`versioneer`](https://github.com/warner/python-versioneer). That means that
+to make a new release the first step is to generate a git tag with the release
+numbers.
+
+Release numbers should be in the format `X.Y.Z`, e.g. `7.4.2` or `7.5.0`.
+
+Currently, all of the build/upload of the releases is handled on Travis-CI and
+Appveyor, but in principle one could build the packages on local machines and
+upload them.
+
+Tagging the commit in GitHub or doing the tag locally and pushing it to GitHub
+will trigger the builds without any further action.
+
+If you want to build locally:
+
++ Build and upload the source distribution (once per release)
+    * `python setup.py sdist` -- generate the source distribution
+    * `twine upload dist/*.tar.gz` -- upload the generated distribution
++ Build and upload binary wheels (once per release *per platform*)
+    * `python setup.py wheel` -- generate binary distribution on the platform
+      on which you are running.
+    * `twine upload dist/*.whl` -- upload the generated distribution
++ Build the conda package (once per release *per platform*)
+    * `conda build vpython.recipe`
+    * `anaconda upload `*recipe_location* -- replace *recipe_location* with
+      the directory output by conda build.
+
+## Releasing the JupyterLab Extension
+
+Please see the instructions in the `labextension` folder for building and
+releasing the JupyterLab extension.