Change Vagrant config to use a private network connection so that the box can get on the internet for live tests.
Add `LiveServiceTestCase` to provide setup for running tests live against the API. Add tests for the auth service and group service based on the live test case. Allows developing directly against the API to verify implementation.
Refactor live tests to use new `configureLiveClient()` method for common client-creation code. Cleans up live test cases.
Add live tests for implemented organizer service methods.

Change `groupKey` on `Organizer` model from `string` to `int` to match API.
Add tests for the implemented `MeetingService` methods.

Add Carbon as dev dependency to use during testing.
Merge branch 'master' into develop
Implement create and delete meeting methods. Live and offline service tests implemented for new methods.

Live delete test depends on create test so that it can clean up after itself.

Client modified to build Guzzle request differently to better accommodate sending JSON in the request body.