Fix encoding problem

For some reason running setup.py with python 3.3.2 on OpenSuse13 64bit gave me

File "setup.py", line 9, in <module>
readme = open(readme_path).read()
File "/usr/lib64/python3.3/encodings/ascii.py", line 26, in decode
return codecs.ascii_decode(input, self.errors)[0]

Fixed by setting encoding to UTF-8 when opening the file