[Issue #351] ci: Improved setup.py fixed problem with the reading of the README.md

Author: scaphilo

setup.py

@@ -1,12 +1,14 @@
-from os import open
 from setuptools import setup, find_packages
 from koalixcrm.version import KOALIXCRM_VERSION
 
+with open("README.md", "r", encoding="utf-8") as readme_file:
+    long_description = readme_file.read()
+
 setup(name='koalix-crm',
       version=KOALIXCRM_VERSION,
       description='koalixcrm is a tiny and easy to use Customer-Relationship-Management'
                   ' Software (CRM) including tiny and easy to use Accounting Software',
-      long_description=open('README.md').read(),
+      long_description=long_description,
       long_description_content_type='text/markdown',
       url='http://github.com/scaphilo/koalixcrm',
       author='Aaron Riedener',