Merge pull request #9868 from Superjomn/fea/docker_cudnn7

update docker from cudnn5 -> cudnn7

Author: luotao1

Dockerfile

@@ -1,6 +1,6 @@
 # A image for building paddle binaries
 # Use cuda devel base image for both cpu and gpu environment
-FROM nvidia/cuda:8.0-cudnn5-devel-ubuntu16.04
+FROM nvidia/cuda:8.0-cudnn7-devel-ubuntu16.04
 MAINTAINER PaddlePaddle Authors <[email protected]>
 
 ARG UBUNTU_MIRROR