TypeError after reload(pytz)

[Christoph Gohlke]

```
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pytz
>>> pytz.__version__
'2016.6.1'
>>> from importlib import reload
>>> reload(pytz)
<module 'pytz' from 'X:\\Python35\\lib\\site-packages\\pytz\\__init__.py'>
>>> pytz.timezone('US/Eastern')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "X:\Python35\lib\site-packages\pytz\__init__.py", line 172, in timezone
    zone = _unmunge_zone(zone)
  File "X:\Python35\lib\site-packages\pytz\__init__.py", line 188, in _unmunge_zone
    return zone.replace('_plus_', '+').replace('_minus_', '-')
TypeError: a bytes-like object is required, not 'str'
```
See also <https://github.com/numpy/numpy/issues/7872>