use multi get ip services

[cheng10]

1. cheng10.cc/ip
2. https://ip.cheng10.cc (aws lambda)

{
client_ip: "27.102.113.138",
timestamp: "2019-08-02T12:57:15.643880"
}

[cheng10]

http://ipecho.net/plain

[cheng10]

allow passing optional args to override ip checking url, like this:
'--ip_checking_url=http://ipecho.net/plain'