Force opening README.rst as utf-8

Causes issues if the locale is not set to utf-8

setup.py

@@ -32,7 +32,7 @@ from setuptools import setup, find_packages, Extension
 from mwparserfromhell import __version__
 from mwparserfromhell.compat import py26, py3k
 
-with open("README.rst") as fp:
+with open("README.rst", **{'encoding':'utf-8'} if py3k else {}) as fp:
     long_docs = fp.read()
 
 tokenizer = Extension("mwparserfromhell.parser._tokenizer",