Setup pytest folder architecture

node-hub/opencv-plot/tests/test_opencv_plot.py

@@ -0,0 +1,2 @@
+def test_placeholder():
+    pass

node-hub/opencv-video-capture/tests/test_opencv_video_capture.py

@@ -0,0 +1,2 @@
+def test_placeholder():
+    pass

node-hub/ultralytics-yolo/tests/test_ultralytics_yolo.py

@@ -0,0 +1,2 @@
+def test_placeholder():
+    pass