Miscellaneous tests

ros_control

/joint_group_position_controller/command makes a robot go to the input position.
- Launch a Gazebo robot: roslaunch rain_gazebo ur5_robotiq.launch
- Switch controllers:
```
rosservice call /controller_manager/switch_controller "start_controllers:
- 'joint_group_position_controller'
stop_controllers:
- 'pos_based_pos_traj_controller'
strictness: 2"
```
- You can test: rostopic pub --once /joint_group_position_controller/command std_msgs/Float64MultiArray "data: [0,0,0,0,0,0]"