[Example] Gradcam- Fixing a link (#13307)

* fixing gradcam

* changed loading parameters code

* fixing type conversions issue with previous versions of matplotlib

* gradcam consolidation

* creating directory structures in utils

* changing location

* empty commit

* fix file lock issue

* fix link

* removing other commits

* remove commit

docs/tutorials/vision/cnn_visualization.md

@@ -22,7 +22,7 @@ from matplotlib import pyplot as plt
 import numpy as np
 
 gradcam_file = "gradcam.py" 
-base_url = "https://github.com/apache/incubator-mxnet/tree/master/docs/tutorial_utils/vision/cnn_visualization/{}?raw=true"
+base_url = "https://raw.githubusercontent.com/apache/incubator-mxnet/master/docs/tutorial_utils/vision/cnn_visualization/{}?raw=true"
 mx.test_utils.download(base_url.format(gradcam_file), fname=gradcam_file)
 import gradcam
 ```