Update dc gan (#6249)
Update dc gan (#6249)

I have updated 2 items:
1. using np.zeros with floats has been deprecated, so I am casting the floats to int's. 
2. using matplotlib instead of cv2 to plot the image. This is because I was running this on a Jupyter notebook on AWS using deep learning AMI, and cv2 does not plot when running Jupyter over ssh, but matplotlib is able to plot both locally and over ssh on AWS EC2.
Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet,Guneet-Dhillon/mxnet