connection options instead of setting REDIS_HOST etc individually

Close #1986

This reverts commit 5135d609b7.

* Allow puma to listen Unix socket

* streaming: Show the whole listening address instead of the port

Port is not always appropriate (e.g. Unix socket)

* streaming: Close server before exiting

This change especially allows to remove Unix socket before exiting.

* Make sure we start at least one streaming worker, even if there's only one CPU and we're in production mode.

* Oops, let's make sure we're counting cpus right too.

* Add eslint to dev dependancies so it gets installed for the repo

yarn add --dev eslint babel-eslint eslint-plugin-reac

project specific version of eslint, you can globally install eslint-cli
if you want the global runtime, or add .bin to your path

* fix eslint errors about inconsitent returns

* eslint ignore the same as git ignore. allows for eslint .

* Add editorconfig file so everyones editor will be setup to follow the same standards

Refresh timelines when streaming API reconnects in the UI

work flawlessly was a nightmare). WARNING: This commit makes the web UI connect to the streaming API instead
of ActionCable like before. This means that if you are upgrading, you should set that up beforehand.