Simplify crawler

[matt-auckland]

On this page https://karate.org.nz/events/, there is a button which links to https://karate.org.nz/events/?ical=1&tribe_display=list

This URL contains all upcoming events in a .ics file.

This file should be able to easily be parsed to get event information.

This is much easier than trying to parse info from the raw event HTML.

1. Download file
2. Parse info into a JSON array of event objects

Still need to figure out how this will eventually automatically hook back into https://github.com/matt-auckland/uoa-karate but for now a manual process can be undertaken