moby: internal Additional property internal is not allowed (docker stack deploy with compose v3 file)

Description

The internal key doesn’t seem to work when creating a network with docker stack deploy and a docker-compose file (v3 format).

Steps to reproduce the issue:

1. create a docker-compose.yml file with this content:

version: '3.0'

networks:
  foo:
    driver: overlay
    internal: true

1. deploy it:

$ docker stack deploy -c docker-compose.yml foo

1. watch it fail 💥:

$ docker stack deploy -c docker-compose.yml foo
internal Additional property internal is not allowed

Describe the results you received:

(see above)

Describe the results you expected:

An internal network to be created 😃

Output of docker version:

$ docker version
Client:
 Version:      1.13.0-rc7
 API version:  1.25
 Go version:   go1.7.3
 Git commit:   48a9e53
 Built:        Fri Jan 13 21:41:57 2017
 OS/Arch:      darwin/amd64

Server:
 Version:      1.13.0-rc7
 API version:  1.25 (minimum version 1.12)
 Go version:   go1.7.3
 Git commit:   48a9e53
 Built:        Fri Jan 13 21:41:57 2017
 OS/Arch:      linux/amd64
 Experimental: true

Output of docker info:

$ docker info
Containers: 2
 Running: 1
 Paused: 0
 Stopped: 1
Images: 606
Server Version: 1.13.0-rc7
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins: 
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
Swarm: active
 NodeID: 62ji4rbm9cp6lluyrz7acl00y
 Is Manager: true
 ClusterID: ap5aksi3rjbalc5zvhrut4rf7
 Managers: 1
 Nodes: 1
 Orchestration:
  Task History Retention Limit: 10
 Raft:
  Snapshot Interval: 10000
  Number of Old Snapshots to Retain: 0
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
 Node Address: 192.168.65.2
 Manager Addresses:
  192.168.65.2:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 03e5862ec0d8d3b3f750e19fca3ee367e13c090e
runc version: 2f7393a47307a16f8cee44a37b262e8b81021e3e
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.9.3-moby
Operating System: Alpine Linux v3.5
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 1.952 GiB
Name: moby
ID: 5OHX:44FP:GRVY:CK7Y:J7R5:P7YY:YMZB:JN4G:HN2G:IWIE:L742:SHNP
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 67
 Goroutines: 353
 System Time: 2017-01-19T16:56:58.766066099Z
 EventsListeners: 2
No Proxy: *.local, 169.254/16
Username: hairyhenderson
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

Additional environment details (AWS, VirtualBox, physical, etc.):

Docker for Mac 1.13.0-rc7-beta37 (15013)