Use io module for Python 2 compatibility

setuptools/command/easy_install.py

@@ -37,6 +37,7 @@ import struct
 import contextlib
 import subprocess
 import shlex
+import io
 
 from setuptools import Command
 from setuptools.sandbox import run_setup
@@ -1801,7 +1802,7 @@ def is_python(text, filename='<string>'):
 def is_sh(executable):
     """Determine if the specified executable is a .sh (contains a #! line)"""
     try:
-        with open(executable, encoding='latin-1') as fp:
+        with io.open(executable, encoding='latin-1') as fp:
             magic = fp.read(2)
     except (OSError, IOError):
         return executable