Adds public registry, instance logging

[craig-willis]

Updates for v1.2 include

• Mount docker socket in Girder
• Add /tmp mount to Girder
• Adds public image registry Add read-only public registry deploy-dev#52
• Adds instance logger Add logger and expose docker socket in girder container deploy-dev#53

[Xarthisius]

In girder service you also need:

1. in environment:
   1. GOSU_USER=girder:girder:<proper docker gid>
   2. HOSTDIR=/
   3. DOMAIN=${domain}
2. I don't think we need scheduler anymore.