Remove iptables dependency

[caizixian]

[duffolonious]

https://github.com/ldx/python-iptables - perhaps use this iptables python binding.

Or if on a router you can use conntrack for information (conntrack-tools) or read conntrack information directly from /proc (if available).

[caizixian]

@duffolonious First of all, thank you for your feedback.

I'm using the iptables python binding which you mentioned. (https://github.com/caizixian/tcpstat/blob/master/requirements.txt)

Thank you for your other suggestions about fetching info. I have been too busy to continue developing this project in recent months, if you have some other brilliant ideas, feel free to submit pull request.