keep_dims is deprecated, use keepdims instead
It's not an error, it's simply notifying you that the code is written using past versions of Tensorlfow and some of the arguments of special methods were going to be deprecated in the future releases of the library. It's ok to be used, but you can also check what version is used and make a virtual environment and install the specified version of the library you want. 

You can run your cell twice in order not to see the warning again.