Improve the topology test suite

Since we had some issues with testing in the past, I propose that we include the hypothesis module for Python into our test suite. Side by side with the pytest module we’re already running as it is compatible with pytest. The hypothesis module allows us to cover a broader range in our parametrization and checks edge cases. As they say it on their page:

It lets you write tests which are parametrized by a source of examples, and then generates simple and comprehensible examples that make your tests fail. This lets you find more bugs in your code with less work.

It is quite powerful and might help us in finding bugs earlier.

[whzup]

Yes, exactly! But now we use it for the topology tests. We just have to return the history and the best cost/pos in the fixture so we can check if it really is the best that has ever been found. I’ll go ahead and write this up. It’s probably a small PR.

[ljvmiranda921]

…add the history of a fixture optimizer to the tests so we can make sure the best cost is the best cost that has ever been found.

Sorry it’s not yet clear to me. How is this different from our *_opt_history() fixtures? Can we reuse these fixtures for the problem? 👍