Add Maven Central badge. (#28)

README.md

@@ -1,8 +1,9 @@
 # The Archives Unleashed Toolkit
 [![Build Status](https://travis-ci.org/archivesunleashed/aut.svg?branch=master)](https://travis-ci.org/archivesunleashed/aut)
-[![Contribution Guidelines](http://img.shields.io/badge/CONTRIBUTING-Guidelines-blue.svg)](./CONTRIBUTING.md)
-[![LICENSE](https://img.shields.io/badge/license-Apache-blue.svg?style=flat-square)](./LICENSE)
 [![codecov](https://codecov.io/gh/archivesunleashed/aut/branch/master/graph/badge.svg)](https://codecov.io/gh/archivesunleashed/aut)
+[![Maven Central](https://maven-badges.herokuapp.com/maven-central/io.archivesunleashed/aut/badge.svg)](https://maven-badges.herokuapp.com/maven-central/io.archivesunleashed/aut)
+[![LICENSE](https://img.shields.io/badge/license-Apache-blue.svg?style=flat-square)](./LICENSE)
+[![Contribution Guidelines](http://img.shields.io/badge/CONTRIBUTING-Guidelines-blue.svg)](./CONTRIBUTING.md)
 
 The Archives Unleashed Toolkit is an open-source platform for analyzing web archives. Tight integration with Hadoop provides powerful tools for analytics and data processing via Apache Spark.
 
@@ -39,4 +40,4 @@ Licensed under the [Apache License, Version 2.0](http://www.apache.org/licenses/
 
 # Acknowledgments
 
-This work is primarily supported by the [Andrew W. Mellon Foundation](https://uwaterloo.ca/arts/news/multidisciplinary-project-will-help-historians-unlock). Additional funding for the Toolkit has come from the U.S. National Science Foundation, Columbia University Library's Mellon-funded Web Archiving Incentive Award, the Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council of Canada, and the Ontario Ministry of Research and Innovation's Early Researcher Award program. Any opinions, findings, and conclusions or recommendations expressed are those of the researchers and do not necessarily reflect the views of the sponsors.
+This work is primarily supported by the [Andrew W. Mellon Foundation](https://uwaterloo.ca/arts/news/multidisciplinary-project-will-help-historians-unlock). Additional funding for the Toolkit has come from the U.S. National Science Foundation, Columbia University Library's Mellon-funded Web Archiving Incentive Award, the Natural Sciences and Engineering Research Council of Canada, the Social Sciences and Humanities Research Council of Canada, and the Ontario Ministry of Research and Innovation's Early Researcher Award program. Any opinions, findings, and conclusions or recommendations expressed are those of the researchers and do not necessarily reflect the views of the sponsors.