Host network for Docker env_type

[Przemysław Rekucki]

Add support for host network mode in docker environment.

{
  "envType": "docker",
  "image": {
    "url": "tomcat:6.0.44",
    "hash": "sha256:4f00109135274b73a9cd8b3a46f43353a095515088e724a442752a62e9cfa3b3"
  },
  "name": "tomcat",
  "tags": [],
  "note": null,
  "options": {
    "net": {
      "host": {}
    }
  }
}