Pin version of libcudnn5 package to 5.0.5
Pin version of libcudnn5 package to 5.0.5

Workaround for a packaging bug with libcudnn5-dev. This package should
have an exact version dependency on the runtime library, see the
debian policy manual:
https://www.debian.org/doc/debian-policy/ch-sharedlibs.html#s-sharedlibs-intradeps

Reported by @cbiffle.

Closes: #131

NVIDIA/nvidia-docker,mvechava/nvidia-docker,mvechava/nvidia-docker,mvechava/nvidia-docker