cast mnist targer to int (#605)

Author: truskovskiyk

torchvision/datasets/mnist.py

@@ -67,7 +67,7 @@ def __getitem__(self, index):
         Returns:
             tuple: (image, target) where target is index of the target class.
         """
-        img, target = self.data[index], self.targets[index]
+        img, target = self.data[index], int(self.targets[index])
 
         # doing this so that it is consistent with all other datasets
         # to return a PIL Image