Clean up

tutorials/pick_and_place/Scripts/SourceDestinationPublisher.cs

-using RosMessageTypes.Geometry;
-using Quaternion = UnityEngine.Quaternion;
 
 public class SourceDestinationPublisher : MonoBehaviour
 {

tutorials/pick_and_place/Scripts/TrajectoryPlanner.cs

     /// <returns></returns>
     private IEnumerator ExecuteTrajectories(MoverServiceResponse response)
     {
-        if (response.trajectories != null)
+        if (response.trajectories.Length > 0)
         {
             // For every trajectory plan returned
             for (int poseIndex  = 0 ; poseIndex < response.trajectories.Length; poseIndex++)