Revert "Add error to setup.py"

This reverts commit 3acab96.

Author: drvinceknight

setup.py

@@ -12,7 +12,7 @@
     long_description = f.read()
 
 # Read in the version number
-exec(open("axelrod/version.py", "r").read()
+exec(open("axelrod/version.py", "r").read())
 
 setup(
     name="Axelrod",