Fix Python 3.x compatibility for setup.py (#332)
Fix Python 3.x compatibility for setup.py (#332)

Without the patch, setup.py fails to run under Python 3.x with pypandoc installed:

```
Traceback (most recent call last):
  File "setup.py", line 16, in <module>
    f.write(long_description)
TypeError: write() argument must be str, not bytes
```
alecthomas/voluptuous,alecthomas/voluptuous