preparation for joss: add paper and biblio, new version of the dump, README...

preparation for joss: add paper and biblio, new version of the dump, README updated, dummy.py for simple testing,

README.md

@@ -67,7 +67,10 @@ More examples, including testing geospatial queries, are available in the `tests
 
 ## Acknowledgments
 
-Data source provider : [INSEE](https://www.insee.fr/)
+Data source provider : 
+- [INSEE](https://www.insee.fr/)
+- [IGN](http://professionnels.ign.fr/contoursiris)
 
-Financial support : Labex [Intelligence des Mondes Urbains (IMU)](http://imu.universite-lyon.fr/projet/hil)
+Financial support : 
+- Labex [Intelligence des Mondes Urbains (IMU)](http://imu.universite-lyon.fr/projet/hil)