Integrate Google Calendar API for adding events to calendar

[utkarsh867]

As an organiser, I want to automatically add events to my Google Calendar so I can manage my schedule better.

As a participant, I want to add an event to my calendar as soon as I register for it so I can keep up with all the events that I registered for.

[98sean98]

Where should this logic be implemented? In the frontend raven side or in phoenix?

Should this google calendar sync behavior work on an event-by-event basis? Or should it just sync all related events? Or should the behavior can be chosen by user in some settings page?

[utkarsh867]

We will have to think about the implementation a bit. The idea is to be able to create a Google Calendar event for someone who registers for an event.