Fix version-checking to allow for versions >= 3
Fix version-checking to allow for versions >= 3

andyneff/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,jbn/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,jbn/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,jbn/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,juhasch/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,andyneff/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,benvarkey/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,ipython-contrib/IPython-notebook-extensions,jcb91/IPython-notebook-extensions,jbn/IPython-notebook-extensions