Script for publishing blockly-demo to app engine

[samelhusseini]

Is your feature request related to a problem? Please describe.
Script for publishing blockly-demo to app engine

Describe the solution you'd like

With gcloud being an npm package: https://www.npmjs.com/package/gcloud, we can add it as a dev dependency and have a deploy script that deploys the app to appengine.

Additional context

[NeilFraser]

Currently one just pushes the "Deploy" button in GoogleAppEngineLauncher. This way it's not an option that external developers end up with. Not sure what problem we're trying to solve here.

[rachel-fenichel]

The problem we're solving for is that we have a lot of manual steps for deployment. Each one is pretty simple, but it would be better to tie them all together into a script.

As a bonus, I believe the google app engine launcher is both deprecated and doesn't work on linux.

@samelhusseini I'm also down to have this in a separate repo with the rest of our tooling, though that seems unnecessary.

[RoboErikG]

Any issue with putting it in blockly-tools?

[rachel-fenichel]

Mostly that the rest of our releasing stuff is over here (in the scripts section in package.json), and we've been moving toward being able to just say npm run release. Pulling in blockly-tooling and linking everything adds complexity and seems nonstandard.

[moniika]

Fixed in #4551
with the caveat that the npm package gcloud is deprecated and so gcloud needs to be manually set up at first.