setup: remove pkg_resources import

setutools 82 dropped pkf_resources module. Also, beside importing
it, it isn't used for anything.

Signed-off-by: Rodrigo M. Duarte <rodrigo.duarte@ossystems.com.br>

Author: mdrodrigo

setup.py

@@ -5,7 +5,6 @@
 import shutil
 import subprocess
 
-import pkg_resources
 from setuptools import setup