mnist_perturbation notebook won't run

A few issues i've found with running this:
1. cell 5, methods[0] is called "input", but the outputs of the uploaded notebook show that it should be called 'random'. Is this correct?

2. cell 9 returns an error on line 37: `project() got an unexpected keyword argument 'input_is_postive_only'` - this appears to be the same as https://github.com/albermax/innvestigate/issues/176

Happy to submit a pull request to fix these if that's helpful