Docker based developer workflow

[arikfr]

This replaces our Vagrant workflow. I am still testing this and working on documentation, but looks like it works nicely.

Added dedicated Docker Compose file (docker-compose.yml) and refactored our Docker image.

Usage:

# Shell 1:
docker-compose up

# Shell 2:
npm run start

To create the database:

docker-compose run --rm server create_db

Then open http://localhost:8080 and start working. The dev server will restart on code changes, but you will need to restart the worker manually (docker-compose restart worker).

TODO:

• Updated instructions on how to create the DB.
• Updated instructions in docs repo (both docker setup & dev guide).

Closes #900, #1377, #628, #1050.

[arikfr]

For those following:

I removed Webpack from Docker Compose:

I realized that it makes more sense to run Webpack on the host machine as usually you will need to install Node.js's tools on the host to enjoy better intelisense and eslint support in the editor.

On top of that, installing Node.js on most developer machines should be relatively easy.

[arikfr]

Added setup wizard for first run of Redash to create the admin user & name the organization (no more "X invited you to join the Redash account of Default").

[arikfr]

Updated dev guide: getredash/website#35
(soon to be merged)