update docs version

docs/conf.py

@@ -51,9 +51,9 @@ copyright = u'2009 - 2014, Aaron R. Quinlan & Neil Kindlon'
 # built documents.
 #
 # The short X.Y version.
-version = '2.21.1'
+version = '2.22.0'
 # The full version, including alpha/beta/rc tags.
-release = '2.21.1'
+release = '2.22.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.