add rooms to json config
update gemspec to new google_middleman version
add Date & DateTime parsing to Event
Simplify next_event functionality for Calendar.

* Use Event started? for checking
* Implement current_event if event.started?
* next_event checks for current_event
* No longer uses sorting since response is sorted
Fix room name as string from config.
Change config filename and update example.
Add sample_config.json to gitignore to remove from history.
Update google calendar example
Fix évent date parsing to use :respond_to
Event respond_to didn't work in production.

* rollback to checking if nil?
Merge pull request #1 from substantial/google-calendar-fix

Google calendar fix