[pepper_bringup] add namespace arg to naoqi_driver.launch

[kochigami]

I added namespace arg instead of adding it as a group name.
This pull-request is related to ros-naoqi/naoqi_driver#81 .
If there is any problem, please let me know.

The result is like this:

roslaunch pepper_bringup pepper_full.launch 
=> 
rosnode list
/pepper_robot
/pepper_robot/camera/bottom_rectify_color
/pepper_robot/camera/camera_nodelet_manager
/pepper_robot/camera/depth_metric
/pepper_robot/camera/depth_metric_rect
/pepper_robot/camera/depth_rectify_depth
/pepper_robot/camera/depth_registered_hw_metric_rect
/pepper_robot/camera/depth_registered_metric
/pepper_robot/camera/depth_registered_rectify_depth
/pepper_robot/camera/depth_registered_sw_metric_rect
/pepper_robot/camera/front_rectify_color
/pepper_robot/camera/ir_rectify_ir
/pepper_robot/camera/points_xyzrgb_hw_registered
/pepper_robot/camera/points_xyzrgb_sw_registered
/pepper_robot/camera/register_depth_front
/pepper_robot/pose/pose_controller
/pepper_robot/pose/pose_manager
/rosout

[kochigami]

I modified this in accordance with the change of ros-naoqi/naoqi_driver#81 .
Travis test fails because this requires the pull-request.

[nlyubova]

+1 @suryaambrose ?

[mikaelarguedas]

Note: the test is failing with this modification to the launchfile

[nlyubova]

right, @mikaelarguedas what should we do with these both requests? should we finish it or leave?

[mikaelarguedas]

This PR is fine, but the "namespace" argument should be added to naoqi_driver.launch that currently doesn't know expose this argument

[kochigami]

same comment as ros-naoqi/naoqi_driver#81