Update setup.py

Remove ez_setup stuff from `setup.py` as well.

setup.py

@@ -1,11 +1,6 @@
 #!/usr/bin/env python
 
-try:
-    from setuptools import setup
-except ImportError:
-    from ez_setup import use_setuptools
-    use_setuptools()
-    from setuptools import setup
+from setuptools import setup
 
 
 import os