PR #3001 from deep0294: Update ReadMe to run ROS2 Unit Test

realsense2_camera/test/README.md

@@ -126,6 +126,15 @@ The xml files mentioned by the command can be directly opened also.
 
 ### Running pytests directly
 
+Note :
+1. All the commands for test execution has to be executed from realsense-ros folder. For example: If the ROS2 workspace was created based on Step 3 [Option2] of [this](https://github.com/IntelRealSense/realsense-ros/blob/ros2-development/README.md#installation).
+Then, the path to execute the tests would be ~/ros2_ws/src/realsense-ros.
+
+		cd ~/ros2_ws/src/realsense-ros
+
+2. Please setup below required environment variables. If not, Please prefix them for every test execution.
+
+		PYTHONPATH=$PYTHONPATH:$PWD/realsense2_camera/test/utils:$PWD/realsense2_camera//launch:$PWD/realsense2_camera//scripts
 
 User can run all the tests in a pytest file directly using the below command: