The way italki told me to sync my calendar just never worked for me, I never see the ical feed update itself. I figured out a better way.
Every time I schedule lessons I:
* Go to my
https://www.italki.com/calendar
* Click "get icalendar feed"
* Click copy, normally they want you to import the address into google, but instead...
* Go to that address, an ICS file with all the events will download
* Go to your gcal settings, mine are at
https://calendar.google.com/calendar/u/0/r/settings/export
* Import the ICS file, and bam, you have events with your italki schedule.
One thing to note, this calendar does not update when you reschedule or cancel. But at least it's guaranteed to be there. Cheers.