Errors in README

[aazuspan]

Hi @stevenpawley, this is an awesome tool. Thanks for building it!

I came across a couple small issues in the readme, and I figured I'd point them out in case they confuse anyone else.

• In the three examples in the Usage section, files, arrays, and layers are passed to file_path, arr, and layers args, but they should all be passed to src instead.
• According to the Raster Prediction section, the predict_type argument can be used to generate probabilities, but I think it doesn't do anything and Raster.predict_proba() should be used instead. Confusingly, Raster.predict() takes any kwargs, so it just ignores the predict_type if it's given and runs as usual. Maybe an error could be thrown for unrecognized kwargs?

[stevenpawley]

Thanks for this, definitely have been neglecting the readme for a while. Updated it now with working examples.