Add support for anonymising ip addresses

[albertpastrana]

There will be different options we can do in here:

• Trucation
• Geo IP to country
• Hashing

References:

• https://security.stackexchange.com/questions/18123/how-to-make-database-of-ip-addresses-anonymous/18178#18178
• https://tools.ietf.org/html/rfc6235
• https://github.com/oschwald/geoip2-golang