Multi-GPU Support 

Hello, I want to use multi-GPU but no mrcnn module is in the project. I wonder whether multi-GPU is supported. Thanks a lot. 
`        # Add multi-GPU support.
        # if config.GPU_COUNT > 1:
        #     from mrcnn.parallel_model import ParallelModel
        #     model = ParallelModel(model, config.GPU_COUNT)`
