Cifar100 added to docs (#318)

added CIFAR100 autoclass in docs

Author: jvmancuso

docs/source/datasets.rst

@@ -86,6 +86,8 @@ CIFAR
   :members: __getitem__
   :special-members:
 
+.. autoclass:: CIFAR100
+
 STL10
 ~~~~~
 

torchvision/datasets/cifar.py

@@ -161,6 +161,10 @@ def download(self):
 
 
 class CIFAR100(CIFAR10):
+    """`CIFAR100 <https://www.cs.toronto.edu/~kriz/cifar.html>`_ Dataset.
+
+    This is a subclass of the `CIFAR10` Dataset.
+    """
     base_folder = 'cifar-100-python'
     url = "https://www.cs.toronto.edu/~kriz/cifar-100-python.tar.gz"
     filename = "cifar-100-python.tar.gz"