Merge pull request #47 from gitter-badger/gitter-badge

[CI] Add a Gitter chat badge to README.md

README.md

@@ -3,7 +3,7 @@
 [![Build status](https://ci.appveyor.com/api/projects/status/bdxsolk0t1uji9rd?svg=true)](https://ci.appveyor.com/project/jajupmochi/graphkit-learn)
 [![codecov](https://codecov.io/gh/jajupmochi/graphkit-learn/branch/master/graph/badge.svg)](https://codecov.io/gh/jajupmochi/graphkit-learn)
 [![Documentation Status](https://readthedocs.org/projects/graphkit-learn/badge/?version=master)](https://graphkit-learn.readthedocs.io/en/master/?badge=master)
-[![PyPI version](https://badge.fury.io/py/graphkit-learn.svg)](https://badge.fury.io/py/graphkit-learn)
+[![PyPI version](https://badge.fury.io/py/graphkit-learn.svg)](https://badge.fury.io/py/graphkit-learn) [![Join the chat at https://gitter.im/graphkit-learn/graphkit-learn](https://badges.gitter.im/graphkit-learn/graphkit-learn.svg)](https://gitter.im/graphkit-learn/graphkit-learn?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 A Python package for graph kernels, graph edit distances and graph pre-image problem.