Added .gitreview.
Added .gitreview.

This patch added .gitreview file to support users who use the git-review
tool.
https://pypi.python.org/pypi/git-review

Change-Id: I7730d9631344df5520648ff75a4df2b382938b70
Signed-off-by: Hideyuki Tai <87b3ecc686f9d387127fb9c6b83e75a0e66a7ae8@necam.com>

opendaylight/nic