Update wheel to include CPython 3.8

Author: mgeier

setup.py

@@ -11,7 +11,7 @@
 
 PYTHON_INTERPRETERS = '.'.join([
     'cp26', 'cp27',
-    'cp32', 'cp33', 'cp34', 'cp35', 'cp36', 'cp37',
+    'cp32', 'cp33', 'cp34', 'cp35', 'cp36', 'cp37', 'cp38',
     'pp27',
     'pp32', 'pp33', 'pp34', 'pp35', 'pp36',
 ])