Update README.rst

note that, without `wheel` installed, the build fails mysteriously

Author: jeffakolb

README.rst

@@ -824,14 +824,16 @@ After the pull request process is accepted, package maintainers will
 handle building documentation and distribution to Pypi.
 
 For reference, distributing to Pypi is accomplished by the following
-commands, ran from the root directory in the repo:
+commands, run from the root directory in the repo (ensure the 
+``twine`` and ``wheel`` packages are installed):
 
 .. code:: bash
 
     python setup.py bdist_wheel
     python setup.py sdist
     twine upload dist/*
 
+
 How to build the documentation:
 
 Building the documentation requires a few Sphinx packages to build the