Fix BUG in Python3.5

[sunbohit]

To make the read_words function can be used in Python3.5 without a BUG "TypeError: a bytes-like object is required, not 'str'"

[zsdonghao]

@sunbohit Thanks, but this modification cannot run under python 3.4 and python 2.7.

     return f.read().replace(*replace).split()
TypeError: Can't convert 'bytes' object to str implicitly

I suggest you to fix it in compatible way.

[sunbohit]

@zsdonghao Now it works?

[zsdonghao]

@sunbohit yes, now it works well with both python 3.4 and 3.5. well done.