Update README.md

Author: jungtaekkim

README.md

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 # BayesO Benchmarks: Benchmark Functions for Bayesian Optimization
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.7577331.svg)](https://doi.org/10.5281/zenodo.7577331)
 [![Build Status](https://github.com/jungtaekkim/bayeso-benchmarks/actions/workflows/pytest.yml/badge.svg)](https://github.com/jungtaekkim/bayeso-benchmarks/actions/workflows/pytest.yml)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)