Add DOI with Zenodo

Author: jiahao

README.md

@@ -7,6 +7,7 @@ Random matrix package for [Julia](http://julialang.org).
 [![Build Status](https://travis-ci.org/jiahao/RandomMatrices.jl.png?branch=master)](https://travis-ci.org/jiahao/RandomMatrices.jl)
 [![Coverage Status](https://coveralls.io/repos/jiahao/RandomMatrices.jl/badge.svg?branch=master&service=github)](https://coveralls.io/github/jiahao/RandomMatrices.jl?branch=master)
 [![codecov.io](https://codecov.io/github/jiahao/RandomMatrices.jl/coverage.svg?branch=master)](https://codecov.io/github/jiahao/RandomMatrices.jl?branch=master)
+[![DOI](https://zenodo.org/badge/5087/jiahao/RandomMatrices.jl.svg)](https://zenodo.org/badge/latestdoi/5087/jiahao/RandomMatrices.jl)
 
 This extends the [Distributions](https://github.com/JuliaStats/Distributions.jl)
 package to provide methods for working with matrix-valued random variables,