doctor: adds logger
doctor: adds logger

Change-Id: Idc9c0f17049b9e6d2d7a0b8dc2bf35778d3c29dd
Signed-off-by: Ryota MIBU <2a020678b95ddf14a5db916807d3fb3b65997655@cq.jp.nec.com>

mywulin/functest,opnfv/functest,opnfv/functest,mywulin/functest