python3: Use `setuptools.setup()` instead of distutils

We need to specify new dependency on `six` module with
`install_requires` which is supported via setuptools.

Signed-off-by: Lumir Balhar <lbalhar@redhat.com>
Signed-off-by: Jiri Kastner <jkastner@redhat.com>
diff --git a/setup.py b/setup.py
index 991cbf9..a146ed7 100755
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 from distutils.sysconfig import get_python_lib
-from distutils.core import setup
+from setuptools import setup
 from os.path import isfile, join
 import glob
 import os
@@ -23,4 +23,5 @@
 Abstractions to extract information from the Linux kernel /proc files.
 """,
       packages = ["procfs"],
+      install_requires = ['six'],
       )