Custom options per role

[dhh]

Allow roles to have their own docker run options. Like:

servers:
  web:
    - 1.1.1.1
  jobs:
    hosts:
      - 1.1.1.2
    cmd: bin/jobs
    options:
      mount: "somewhere"
      add-host: true

Will result in job containers being started with:

docker run --detach --restart unless-stopped ... --mount \"somewhere\" --add-host my/app:999 bin/jobs