Added support for IPv6 addresses

[jkaniuka]

While using IPv6, you have to use brackets ([]) to separate the IPv6 address from the port number - see below:

    config["mycottool"] = {
        "COT_URL": "tls://[2001:0db8:85a3:0000:0000:8a2e:0370:7334]:8089"
    }

[jkaniuka]

@ampledata