builtin/docker: Add Binds, Labels and Networks config options

[briancain]

This pull request introduces three new config options for the docker platform for deploys:

• Labels
• Networks
• Binds

It allows users to label their deployed container, as well as connect additional networks.

Fixes #1064

[prabirshrestha]

given that it seems small can we also have volume support? For example I would like to persist traefik certs in docker volume.

[briancain]

@prabirshrestha For sure, I've implemented that as Binds now. I think we'd want Volumes to match what the docker client supports, which ends up being a lot more config options. Binds should get us close for now and is the easiest path forward for users just wanting to share a folder to the container, and if it makes sense down the road we can use Volumes for more robust configuration.