Update the Python versions supported in setup.py

Author: nedbat

setup.py

@@ -6,7 +6,7 @@
 the code analysis tools and tracing hooks provided in the Python standard
 library to determine which lines are executable, and which have been executed.
 
-Coverage.py runs on Pythons 2.3 through 3.2.
+Coverage.py runs on Pythons 2.3 through 3.3, and PyPy 1.8.
 
 Documentation is at `nedbatchelder.com <%s>`_.  Code repository and issue
 tracker are at `bitbucket.org <http://bitbucket.org/ned/coveragepy>`_.