Fix to "ValueError: could not convert string to float:"

When I try to run the code with Rule Agent's prams, I got this:
**ValueError: could not convert string to float:**
My solution is changing the file-pointer loading style from "rb" to "r", and it works for me.
Two place need to fix:

- line 50 in nlu.py

- line138 in nlg.py

I know someone may not encounter the error, and just could enjoy the code perfectly.
