Update Readme.md

Author: hsmurali

Readme.md

@@ -76,7 +76,6 @@ optional named arguments:
 ```
 
 [![DOI](https://zenodo.org/badge/424442689.svg)](https://zenodo.org/badge/latestdoi/424442689)
-[![DOI]](https://doi.org/10.1093/nar/gkad158)
 
 ## References
 Ghodsi, M., Liu, B. & Pop, M. DNACLUST: accurate and efficient clustering of phylogenetic marker genes. BMC Bioinformatics 12, 271 (2011). https://doi.org/10.1186/1471-2105-12-271