Update readme with better badges.

Author: arthurdouillard

README.md

@@ -2,8 +2,8 @@
 
 # PLOP: Learning without Forgetting for Continual Semantic Segmentation
 
-[![Paper](https://img.shields.io/badge/arXiv-2011.11390-critical)](https://arxiv.org/abs/2011.11390)
-[![Conference](https://img.shields.io/badge/CVPR-2021-important)](https://arxiv.org/abs/2011.11390)
+[![Paper](https://img.shields.io/badge/arXiv-2011.11390-brightgreen)](https://arxiv.org/abs/2011.11390)
+[![Conference](https://img.shields.io/badge/CVPR-2021-blue)](https://arxiv.org/abs/2011.11390)
 
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