Upgrade google-spreadsheet to v3.0

[seasoprano]

Google is deprecating their v3 sheets API on March 3, 2020 The 2.x version of google-spreadsheet uses that and will stop working after March 3, so we need upgrade to the latest version (v3.x) https://github.com/theoephraim/node-google-spreadsheet

This upgrade introduces a lot of breaking changes so all handlers need to be updated

Progress:

• [x] readSheetHandler.js
• [x] writeSheetHandler.js
• [x] submitSurveyHandler.js