[setup] Enforce opening README.rst in utf-8

setup.py

@@ -26,6 +26,7 @@
 ###############################################################################
 
 from setuptools import setup, find_packages
+from io import open
 
 # The only thing we do in this file is to call the setup() function with all
 # parameters that define our package.
@@ -38,7 +39,7 @@ setup(
     license='AGPLv3',
     author='Idiap Research Institute',
     author_email='beat.support@idiap.ch',
-    long_description=open('README.rst').read(),
+    long_description=open('README.rst', encoding="utf-8").read(),
 
     # This line is required for any distutils based packaging.
     packages=find_packages(),