Partitions a list according to some discrete ordering, e.g.
wheel < numpy
numpy < scikit
Then using an input like this
scikit
numpy
more-stuff
wheel
it can partition it into three parts by running the module
$python -m partition test/order.txt test/requirements.txt
['wheel']
['numpy']
['scikit', 'more-stuff']
Returns a sequence of list, with the minimal number of parts needed to satisfy all conditions.