Use Meetup API to pull user info

[TheBanditDave]

After user is authenticated, we need to pull their user info from MeetUp and store it in local storage. Then send the user info to the attendee list in backend.

[glitchedmob]

We only need to send that user info when the user checks in

[bpomerenke]

got this working on web and mobile (have to use 2 different client ids because the base urls are different). I'm working on a branch right now that posts the user data to the api on checkin, however it doesn't appear the api is finished so it's just posting to a dummy endpoint.