Send uip using systeminfo

[primal100]

Hey,

In Saleor I want to send uip as an additional attribute. This is used to provide provide location data to Google Measurement Protocol. I managed to do this without any changes to google measurement protocol but it's probably not the "correct" way, as it involves sending a dictionary instead of a SystemInfo instance.

Saleor version:

My version

def report_view(client_id, ip, path, language, headers):
    host_name = headers.get('HTTP_HOST', None)
    referrer = headers.get('HTTP_REFERER', None)
    pv = ga.PageView(path, host_name=host_name, referrer=referrer)
    #extra_info = ga.SystemInfo(language=language) #old line
    extra_info = [{'ul': language, 'uip': ip}] #new line
    extra_headers = {}
    user_agent = headers.get('HTTP_USER_AGENT', None)
    if user_agent:
        extra_headers['user-agent'] = user_agent
    _report(client_id, pv, extra_info=extra_info, extra_headers=extra_headers)

I was thinking of making a pull request to Saleor to allow sending the uip (possibly configurable by a setting). But I think the way I'm doing, using a dictionary is not the correct way. But the SystemInfo class confuses me. Is it possible to modify it to add additional, optional attributes such as uip.