Synch shifts and jobs with google calendar Merged

Allow tasks to export and synch to Google Calendar, and/or Calendly and similar.

We would like our students to be able to see what slots are available for their instructor and make a booking.

Logging into Air Maestro can be slow and requires clicking through many levels, whereas Google Calendar and other apps have immediate visibility on phones.

Export from roster or task scheduler is all that would be required.