Use setup.cfg for long_description

Author: ktns

setup.cfg

@@ -1,3 +1,5 @@
+[metadata]
+long_description = file: README.rst
 [bdist_wheel]
 # This flag says that the code is written to work on both Python 2 and Python
 # 3. If at all possible, it is good practice to do this. If you cannot, you

setup.py

@@ -7,17 +7,12 @@
 import os
 from setuptools import setup
 
-cwd = os.path.dirname(os.path.abspath(__name__))
-
-long_description = open(os.path.join(cwd, 'README.rst'), 'r').read()
-
 setup(name='uModbus',
       version='1.0.3',
       author='Auke Willem Oosterhoff',
       author_email='[email protected]',
       description='Implementation of the Modbus protocol in pure Python.',
       url='https://github.com/AdvancedClimateSystems/umodbus/',
-      long_description=long_description,
       license='MPL',
       packages=[
           'umodbus',