Make it possible to change flip method

[peter-moran]

The flip method (set by nvvidconv flip-method=2 in the pipeline) should be able to be changed though ROS launch arguments. Different cameras than the one tested may pass the video in different orientations.

[vnguyen13]

I am using the Jetbot and the camera needs to be flipped upside down. What value should I use to flip it? I've tried 0, 1, 2, and 3. I've tried running "catkin_make" after changing it. It doesn't seem to be taking the change.

EDIT: Nevermind! Found it in the "src/jetson_csi_cam/jetson_csi_cam.launch" file.