Add Dynflow development and production mode

If `Katello.config.dynflow.remote` is set to `true` Dynflow runs in
Delayed::Worker (rake jobs:work) communicating over socket with Katello’s
web server(s).

If `Katello.config.dynflow.remote` is set to `false` Dynflow runs inside
Katello’s web server.

By default `remote` is set to true in production and to `false` in
development.