feat: #168395616 - automation of registry entry

[gjj]

In this MR, we demonstrate the usage of Google Sheets as an alternative registry storage, instead of the static registry.json. This is so that we can do some fun stuff (automation, etc.) with Google Sheets.

User story

• https://www.pivotaltracker.com/story/show/168395616

❗ 29 Jul edit: We're waiting for general availability of FormSG webhooks

Key changes

• In feat: automated registry verify#7, added googleApiKey into OpenCertsVerificationManagerOptions

• verify now needs to have googleApiKey: GOOGLE_API_KEY passed in

• Publicly inspectable Google Sheets registry: https://docs.google.com/spreadsheets/d/1nhhD3XvHh2Ql_hW27LNw01fC-_I6Azt_XzYiYGhkmAU/edit#gid=103906216

Discovery

• Google Sheets API is rate-limited to 500 read requests per 100 seconds, with no other limits per day (write requests are counted separately, but we didn't use that), source

Things to note (in case anyone else faces the same issues):

• Please use 2 Google API keys: one set to no restrictions to be used by Jest (i.e. for console), another with HTTP referrer restrictions to be used by the web. The key with the web restriction will not work in the command-line

• opencerts-website uses verify#feat/automated-registry - if verify#feat/automated-registry is force pushed, must npm uninstall github.com/OpenCerts/verify.git#feat/automated-registry then reinstall again

• when npm installing git branches, make sure the branch has the dist files

• Dependencies like verify do not access environment variables, must pass googleApiKey: GOOGLE_API_KEY via options

Todo

• Cache spreadsheet JSON for x minutes, to address rate limit