Update to 0.3.0 (#207)

tutorials/pick_and_place/PickAndPlaceProject/Packages/manifest.json

     "com.unity.ide.visualstudio": "2.0.3",
     "com.unity.ide.vscode": "1.2.2",
     "com.unity.robotics.ros-tcp-connector":
-    "https://github.com/Unity-Technologies/ROS-TCP-Connector.git?path=/com.unity.robotics.ros-tcp-connector#dev",
-    "com.unity.robotics.urdf-importer": "https://github.com/Unity-Technologies/URDF-Importer.git?path=/com.unity.robotics.urdf-importer#v0.2.0",
+    "https://github.com/Unity-Technologies/ROS-TCP-Connector.git?path=/com.unity.robotics.ros-tcp-connector#v0.3.0",
+    "com.unity.robotics.urdf-importer": "https://github.com/Unity-Technologies/URDF-Importer.git?path=/com.unity.robotics.urdf-importer#v0.3.0",
     "com.unity.test-framework": "1.1.18",
     "com.unity.textmeshpro": "3.0.1",
     "com.unity.timeline": "1.4.3",