Setup.py/Python 3 fails as expects a byte stream instead of str

setup.py

@@ -49,7 +49,7 @@ if __name__ == "__main__":
         from pypandoc import convert
         long_description = convert("README.md", "rst")\
                            .translate({ord("\r"): None})
-        with open("README.rst", "wb") as readme:
+        with open("README.rst", "w") as readme:
             readme.write(long_description)
     else:
         long_description = open("README.md").read()