bind waitForService in python

Change-Id: I07fc6a0e80a5f85889289930f184fc5b0a09ad5f
Reviewed-on: http://gerrit.aldebaran.lan/44185
Reviewed-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Reviewed-by: rvarannes <rvarannes@aldebaran-robotics.com>
Tested-by: rvarannes <rvarannes@aldebaran-robotics.com>