Fixes cpython version requirements

docs/includes/introduction.txt

@@ -38,7 +38,7 @@ What do I need?
 
 Celery version 3.0 runs on,
 
-- Python (2.5, 2.6, 2.7, 3.2, 3.3)
+- Python (2.6, 2.7, 3.3, 3.4)
 - PyPy (1.8, 1.9)
 - Jython (2.5, 2.7).