SubItUp Google Calendar Integration

UPDATES: Users can now select shifts in larger time frames and move between different time frames. The app now uses less-sensitive authorization scopes by creating a secondary calendar rather than modifying the primary one. Bug Fixes: More rigid detection for if the shift is assigned to the user or not. Proper behavior when requests fail due to access token time outs. Bug Fix: Added TimeZone detection and ability to change the timezones. Open Source Github Repository: https://github.com/chriskim2273/SubItUp-Google-Calendar-Integration