Replace reasoner.jar with Robot

[gaurav]

Robot is a command-line tool that can provide reasoned OWL axioms (see https://github.com/ontodev/robot/blob/master/examples/README.md#reasoning). If we can then read them into Python and process them in a sensible way, that might be a better way of running reasoner-based tests than writing our own reasoner stub to do it.

Also, we could look into getting our Shapes code into Robot, and then all our testing can go through that!