This adds a JS client for the OAPI interface, and introduces the SocketIO
stuff into Flamenco Manager itself.
To build & run:
- in `web/manager-api` run `npm install`
- in `web/manager-api` run `npm link`
- in `web/app` run `npm install`
- in `web/app` run `npm link flamenco-manager`
- in `web/app` run `yarn serve`
This may not be a complete list, but at least some of those steps are
necessary.
