Bug#904359: pandas 0.23.3 update needed for Python 3.7 compatibility

[Matthias Klose]

Control: tags -1 + patch

I packaged 0.23.1, removing the tests applied upstream, and adjusting other
patches.  I ignored test failures for a first build, so that the package can be
built for 3.7, and we can make progress on other packages relying on pandas.

packaging can be found at
https://launchpad.net/ubuntu/+source/pandas/0.23.3-0ubuntu1