Bump opencv-python in /CV/robust_vessel_segmentation

Bumps [opencv-python](https://github.com/skvark/opencv-python) from 3.4.3 to 4.2.0.32.
- [Release notes](https://github.com/skvark/opencv-python/releases)
- [Commits](https://github.com/skvark/opencv-python/commits)

---
updated-dependencies:
- dependency-name: opencv-python
  dependency-type: direct:production
...

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Author: dependabot[bot]

CV/robust_vessel_segmentation/requirements.txt

@@ -1,4 +1,4 @@
 matplotlib==2.2.2
 numpy==1.16.4
-opencv-python==3.4.3
+opencv-python==4.2.0.32
 paddlepaddle-gpu==1.6.2