Update to seaborn 0.9.0?

[justbennet]

We were getting warnings from seaborn about deprecated functions.

Those were reported by the Pandas team and others to the seaborn maintainer, who fixed them in release 0.9.0. The errors were

Traceback (most recent call last):
  File "/usr/local/aroma/ICA-AROMA-a629eb70/ICA_AROMA.py", line 226, in <module>
    outDir)
  File "/usr/local/aroma/ICA-AROMA-a629eb70/classification_plots.py", line 170, in classification_plot
    hist_kws={'alpha': 0.2})
  File "/usr/local/aroma/python/lib/python2.7/site-packages/seaborn/distributions.py", line 208, in distplot
    bins = min(_freedman_diaconis_bins(a), 50)
  File "/usr/local/aroma/python/lib/python2.7/site-packages/seaborn/distributions.py", line 29, in _freedman_diaconis_bins
    h = 2 * iqr(a) / (len(a) ** (1 / 3))
TypeError: len() of unsized object
/usr/local/aroma/python/lib/python2.7/site-packages/seaborn/categorical.py:462: FutureWarning: remove_na is deprecated and is a private function. Do not use.
  box_data = remove_na(group_data)
/usr/local/aroma/python/lib/python2.7/site-packages/matplotlib/axes/_axes.py:6448: UserWarning: The 'normed' kwarg is deprecated, and has been replaced by the 'density' kwarg.

Perhaps you would consider updating the requirement from seaborn 0.8.0 to 0.9.0, if that doesn't introduce additional issues?

[maartenmennes]

addressed in ea166b9