Left out 'python' in hashbang, update setup to use env, too.

Left out 'python' in hashbang, update setup to use env, too.

setup.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 import sys, os
 from setuptools import setup

twython/twython.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env
+#!/usr/bin/env python
 
 """
     Twython is a library for Python that wraps the Twitter API.