Add jazzband header

CONTRIBUTING.rst

+[![Jazzband](https://jazzband.co/static/img/jazzband.svg)](https://jazzband.co/)
+
+This is a [Jazzband](https://jazzband.co/) project.
+By contributing you agree to abide by the
+[Contributor Code of Conduct](https://jazzband.co/docs/conduct) and follow the
+[guidelines](https://jazzband.co/docs/guidelines).
+
 Contribute
 ==========
 
@@ -10,4 +17,4 @@ Contribute
    Make sure to add yourself to *AUTHORS*.
 
 Otherwise, if you simply wants to suggest a feature or report a bug, create an issue :
-https://github.com/cyberdelia/django-pipeline/issues
+https://github.com/jazzband/django-pipeline/issues