Remove some old commented yaml
Remove some old commented yaml

Originally copied from `zenmode`, these are obviously useless.
jcb91/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,moble/jupyter_boilerplate,ipython-contrib/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,juhasch/IPython-notebook-extensions