Update protobuf to 3.6.1.3 by indirectly updating grpc to 1.19.0
Update protobuf to 3.6.1.3 by indirectly updating grpc to 1.19.0

This PR updates protobuf to 3.6.1.3 by indirectly updating
grpc to 1.19.0.

This allows building with bazel 0.22.0.

This fix fixed 126.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io,tensorflow/io