Update README.md

Author: mingdeyu

README.md

@@ -6,7 +6,7 @@
   [![REF](https://img.shields.io/badge/REF-Linked%20GP-informational)](https://doi.org/10.1137/20M1323771)
   [![REF](https://img.shields.io/badge/REF-Deep%20GP-informational)](https://doi.org/10.1080/00401706.2022.2124311)
   [![REF](https://img.shields.io/badge/REF-Linked%20DGP-informational)](https://arxiv.org/abs/2306.01212)
-  [![python](https://img.shields.io/badge/Python-dgpsi%20v2.1.6-informational)](https://github.com/mingdeyu/DGP)
+  [![python](https://img.shields.io/badge/Python-dgpsi%20v2.2.0-informational)](https://github.com/mingdeyu/DGP)
   ![CRAN_License](https://img.shields.io/cran/l/dgpsi?color=green)
 
 The R package `dgpsi` provides R interface to Python package [`dgpsi`](https://github.com/mingdeyu/DGP) for deep and linked Gaussian process emulations.