Test of AGV + robot arm + gripper

The robot test is based on the mmo500 robot from Neobotix company. This company provides simulation packages to test their robots with ROS. This mmo500 robot contains an AGV with two lasers, a UR10 robot arm and a three-finger gripper from Shadow Robot Company. I tested AGV moving by sending cmd_vel message, UR10 robot arm moving and grasping with the three-finger gripper. They can all work properly.

Update second exercise

Several APIs are added to let users take control of both color filters and shape segmentation filters. Currently, we can also check the result of color filters with the image windows in GUI because we can choose to only allow one color filter running at one time. The documentation of second exercise is also updated. After recording a better solution video, Pull Request will be made to publish exercise two: Machine Vision.