Update _base.py

IPython.display replaced by IPython.core.display as IPython.display does not exist in recent version of IPython
source: http://ipython.org/ipython-doc/2/api/generated/IPython.core.display.html
Update test_ordination.py

IPython.display replaced by IPython.core.display
Merge pull request #699 from jradinger/patch-2

Update _base.py