BLD: drop support for python 3.2

[jreback]

someone want to sample the scientific stack and see who still supoorts 3.2?

[jorisvandenbossche]

There was a small mention of this on the numpy mailing list: http://mail.scipy.org/pipermail/numpy-discussion/2014-March/069643.html, but numpy/scipy still support it I think
IPython has already dropped it: http://mail.scipy.org/pipermail/ipython-dev/2013-August/012177.html (but they are always a bit quicker)

scikit-learn seems to only support >= 3.3: http://scikit-learn.org/stable/install.html
Also matplotlib seems like the same, only >=3.3: http://matplotlib.org/users/installing.html#required-dependencies, matplotlib/matplotlib#3192

[jreback]

windows builds are now dropping 3.2, so this is on tap for 0.17.0