(WIP) gmail api instead of smtp

[evanlohn]

This branch has some boilerplate that lets you run the main script with the gmail API.... if you have a client_secret.json locally in your repo that comes from a Google Project with the GMail API's "send" endpoint enabled. I set my own up to test this out; I could push it but then anyone could pretend to be our project when making requests to Google Mail I think... Also, even if everyone were to somehow get their own client secret, they need to get past an "unverified app" screen to get OAuth to work. And, even if I was to push my client_secret.json, we would still only be able to let 100 email addresses use the service before needing verification from Google (see https://support.google.com/cloud/answer/7454865 )

I mentioned a few more details about the "where to put the client secret" problem in Issue #5. Of course, we shouldn't merge this until we fix the above problem. If this project was a webpage (see issue #9 ), the confusion of where to put the client secret would be resolved, but being verified by Google would still be required to go past 100 users (and get rid of the scary "unverified app" screen during OAuth)

[alandgton]

Hey Evan, thanks for working on this! It seems like we're blocked on using the gmail api until we can get this script ported to some cloud service. The application is dockerized now so I'm thinking we could use AWS ECS (https://aws.amazon.com/ecs/).

But yeah, as you mentioned, google is only going to give us 100 tokens for free. If we were going to proceed with this, we would need some $$$ for the amazon servers and google's blessings LOL. In any case, I guess we'll wait and see what we can do once we get a front-end up and running.