Adding fw_max_speed_fwd and /ubiquity_motor/fw_max_speed_rev to robot.yaml

[JanezCim]

Solving https://github.com/UbiquityRobotics/pi_image2/issues/39

To test:

cd ~/catkin_ws/src/
git clone https://github.com/UbiquityRobotics/magni_robot.git -b feature-newrobotyaml-params
cd ~/catkin_ws/
catkin_make -j2
source devel/setup.bash

addfw_max_speed_fwd: 100 and fw_max_speed_rev: -100 into /etc/ubiquity/robot.yaml under ubiquity_motor:

ubiquity_motor:
  fw_max_speed_fwd: 100
  fw_max_speed_rev: -100

then

sudo systemctl restart magni-base.service

see if params have been set:

rosparam get /ubiquity_motor/fw_max_speed_fwd
rosparam get /ubiquity_motor/fw_max_speed_rev

[mjstn]

ok now with 104

[JanezCim]

I will merge this after we release beta2 image so we dont introduce new potential problems