update readme.

README.md

 # Astrocyte ATAC-seq analysis Workflow Package
 
-[![pipeline Status](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/master/pipeline.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/master)
-[![Coverage Report](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/master/coverage.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/master)
-[![Nextflow](https://img.shields.io/badge/nextflow-%E2%89%A50.24.0-brightgreen.svg
-)](https://www.nextflow.io/)
-[![Astrocyte](https://img.shields.io/badge/astrocyte-%E2%89%A50.1.0-blue.svg)](https://astrocyte-test.biohpc.swmed.edu/static/docs/index.html)
-
+|*master*|*dev*|
+|:-:|:-:|
+|[![pipeline status](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/master/pipeline.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/master)|[![pipeline status](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/dev/pipeline.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/dev)|
+|[![coverage report](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/master/coverage.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/master)|[![coverage report](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/badges/dev/coverage.svg)](https://git.biohpc.swmed.edu/BICF/Astrocyte/atacseq_analysis/commits/dev)|
+
+[![Nextflow](https://img.shields.io/badge/nextflow-%E2%89%A50.31.0-brightgreen)](https://www.nextflow.io/)
+[![Astrocyte](https://img.shields.io/badge/astrocyte-%E2%89%A50.2.0-blue)](https://astrocyte-test.biohpc.swmed.edu/static/docs/index.html)
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3526148.svg)](https://doi.org/10.5281/zenodo.3526148)
 
 ## Introduction
 BICF ATAC-seq is a bioinformatics best-practice analysis pipeline used for ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) data analysis at [BICF](http://www.utsouthwestern.edu/labs/bioinformatics/) at [UT Southwestern Department of Bioinformatics](http://www.utsouthwestern.edu/departments/bioinformatics/).