Added support for specifiying insecure_docker_registry_list in manifest
Added support for specifiying insecure_docker_registry_list in manifest

properties:
  garden:
    insecure_docker_registry_list:
    - IP1
    - IP2

[finishes #89106586]

cloudfoundry-incubator/garden-linux-release,Pivotal-DataFabric/garden-linux-release,luan/garden-linux-release,Pivotal-DataFabric/garden-linux-release,tushar-dadlani/garden-linux-release,cloudfoundry-incubator/garden-linux-release,cloudfoundry-incubator/garden-linux-release,totherme/garden-linux-release,luan/garden-linux-release,cloudfoundry-incubator/garden-linux-release,totherme/garden-linux-release,totherme/garden-linux-release,Pivotal-DataFabric/garden-linux-release,luan/garden-linux-release,tushar-dadlani/garden-linux-release,totherme/garden-linux-release,Pivotal-DataFabric/garden-linux-release,tushar-dadlani/garden-linux-release,tushar-dadlani/garden-linux-release,luan/garden-linux-release,cloudfoundry-incubator/garden-linux-release