add note about installing from git

and a little snark

docs/installation.rst

@@ -3,6 +3,19 @@
 Installation
 ============
 
+Important Temporary Note
+++++++++++++++++++++++++
+Sarah has been locked out of her pypi.org account (???) which means that you can't pip install
+the latest version of `orbitize`. If you want to install version 3, you can install the 
+version of the code on github using:
+
+.. code-block:: bash
+
+	$ pip install git+https://github.com/sblunt/orbitize.git
+
+If you're reading this, please upvote Sarah's request to reinstate her pypi.org account: https://github.com/pypi/support/issues/3898
+
+
 For Users
 +++++++++