Added support for checking in users

- added page with user list
- added calls to api
- added support for checkin call in the api client
- adjusted frontend/css
Merge branch 'new-api-client-refactoring' into checkin-page

Conflicts:
	composer.json
	composer.lock
	src/Raffle/MeetupService.php
Refactoring for new API Client.
Updating to latest API client
Updating api client.
Added OAuth Handshake.

Checkin page now gets the user credentials to do checkins, no longer a security issue.
Working draft of checkin functionality
Merge pull request #13 from AmsterdamPHP/redis-checkin

Local Checkin
Updated copyright notice
Cleaned up CSS and markup
Styled checkin link
Added whitespace
Added hover cursor for checkin
Responsive logo
Revert "Responsive logo"

This reverts commit b3e9e770ee07b2dc2fd7f31056dfd4888d967f72.
Added breakpoint for responsive logo
Increased breakpoint
Fixed breakpoint style
Tuned breakpoint
Added background size