Merge pull request #289 from gvwilson/fixing-citation

Updating CITATION file

Author: Greg Wilson

CITATION

@@ -1,5 +1,6 @@
 Please cite as:
 
-Azalee Bostroem and Trevor Bekolay (eds):
-"Software Carpentry: Programming with Python."
-Version 5.3, May 2015, 10.5281/zenodo.27351.
+Azalee Bostroem, Trevor Bekolay, and Valentina Staneva (eds):
+"Software Carpentry: Programming with Python."  Version 2016.06, June
+2016, https://github.com/swcarpentry/python-novice-inflammation,
+10.5281/zenodo.57492.