include_email param in verify_credentials not working

Hello Team,

Thanks for the fantastic job, I am loving Twython!! However, I ran into a small issue, I hope you'd have seen it already, and might have a solution for me. "include_email" parameter isn't working for me, I am not able to get user email. Yes, I've enabled "Request email address" in "Advanced Permissions". I've tried the following variations:

1. include_email=1
2. include_email="1"
3. include_email = True
4. include_email = "true"
5. include_email= "True"

I don't see what else can I try. Can you please help?