downgrade required version of msgpack-python

For Ubuntu 14.04, downgrade the required version of msgpack-python.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
contrib: import tinyrpc library

https://pypi.python.org/pypi/tinyrpc/0.5
https://github.com/mbr/tinyrpc

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ryu.lib.hub: add logging wrapper for wsgi server

This patch adds a wrapper to relay the log of the wsgi server to the logger.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>