chore: make setup compatible with pip > 9.0.3

Author: snejku

setup.py

@@ -1,8 +1,12 @@
 import os
 from setuptools import setup, find_packages
-from pip.req import parse_requirements
 from pip.download import PipSession
 
+try:
+    from pip._internal.req import parse_requirements
+except ImportError:
+    from pip.req import parse_requirements
+
 version = '0.2.2'