Add the ability to create events just from a meetup or eventbrite URL

- Adds classes to handle talking to meetup and eventbrite API
- Determines correct API to use based on URL
- Devs should add Meetup and Eventbrite keys to their local application.yml config
Fix tests
Merge pull request #135 from southpolesteve/eventbrite

Add the ability to create events just from a meetup or eventbrite URL