compose: ERROR: In file './docker-compose.yml' service 'version' doesn't have any configuration options. All top level keys in your docker-compose.yml must map to a dictionary of configuration options.

I’m trying to follow docker-birthday-3/tutorial.md and I’m getting following error:

$ docker-compose up -d
ERROR: In file './docker-compose.yml' service 'version' doesn't have any configuration options. All top level keys in your docker-compose.yml must map to a dictionary of configuration options.
$ cat docker-compose.yml 
version: "2"

services:
  voting-app:
    build: ./voting-app/.
    volumes:
     - ./voting-app:/app
    ports:
      - "5000:80"
    networks:
      - front-tier
      - back-tier

  result-app:
    build: ./result-app/.
    volumes:
      - ./result-app:/app
    ports:
      - "5001:80"
    networks:
      - front-tier
      - back-tier

  worker:
    image: manomarks/worker
    networks:
      - back-tier

  redis:
    image: redis:alpine
    container_name: redis
    ports: ["6379"]
    networks:
      - back-tier

  db:
    image: postgres:9.4
    container_name: db
    volumes:
      - "db-data:/var/lib/postgresql/data"
    networks:
      - back-tier

volumes:
  db-data:

networks:
  front-tier:
  back-tier:
$ git status | grep docker-compose.yml 
$ 

docker version:

$ docker version
Client:
 Version:         1.9.1
 API version:     1.21
 Package version: docker-1.9.1-25.el7.centos.x86_64
 Go version:      go1.4.2
 Git commit:      78ee77d/1.9.1
 Built:           
 OS/Arch:         linux/amd64

Server:
 Version:         1.9.1
 API version:     1.21
 Package version: docker-1.9.1-25.el7.centos.x86_64
 Go version:      go1.4.2
 Git commit:      78ee77d/1.9.1
 Built:           
 OS/Arch:         linux/amd64
$ 

docker info:

$ docker info
Containers: 0
Images: 52
Server Version: 1.9.1
Storage Driver: devicemapper
 Pool Name: docker-253:1-4161645-pool
 Pool Blocksize: 65.54 kB
 Base Device Size: 10.74 GB
 Backing Filesystem: 
 Data file: /dev/loop0
 Metadata file: /dev/loop1
 Data Space Used: 1.495 GB
 Data Space Total: 107.4 GB
 Data Space Available: 105.9 GB
 Metadata Space Used: 2.826 MB
 Metadata Space Total: 2.147 GB
 Metadata Space Available: 2.145 GB
 Udev Sync Supported: true
 Deferred Removal Enabled: false
 Deferred Deletion Enabled: false
 Deferred Deleted Device Count: 0
 Data loop file: /var/lib/docker/devicemapper/devicemapper/data
 Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
 Library Version: 1.02.107-RHEL7 (2015-12-01)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.10.0-327.13.1.el7.x86_64
Operating System: CentOS Linux 7 (Core)
CPUs: 8
Total Memory: 15.43 GiB
Name: X
ID: L6S7:FZCO:YA5M:KSZP:VOKX:CD5H:HHDD:AXGO:XHTS:MF3E:IGKZ:KQ4O
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
$ 

more: I update docker-compose (from 1.5.2 to 1.7.0) and original error went away, yet another error appeared:

$ docker-compose version
docker-compose version 1.7.0, build 0d7bf73
docker-py version: 1.8.0
CPython version: 2.7.9
OpenSSL version: OpenSSL 1.0.1e 11 Feb 2013
$ docker-compose up -d
ERROR: The Docker Engine version is less than the minimum required by Compose. Your current project requires a Docker Engine of version 1.10.0 or greater.
$ docker version
Client:
 Version:         1.9.1
 API version:     1.21
 Package version: docker-1.9.1-25.el7.centos.x86_64
 Go version:      go1.4.2
 Git commit:      78ee77d/1.9.1
 Built:           
 OS/Arch:         linux/amd64

Server:
 Version:         1.9.1
 API version:     1.21
 Package version: docker-1.9.1-25.el7.centos.x86_64
 Go version:      go1.4.2
 Git commit:      78ee77d/1.9.1
 Built:           
 OS/Arch:         linux/amd64
$ cat /etc/redhat-release 
CentOS Linux release 7.2.1511 (Core) 
$ uname -a
Linux X 3.10.0-327.13.1.el7.x86_64 #1 SMP Thu Mar 31 16:04:38 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
$ rpm -q docker
docker-1.9.1-25.el7.centos.x86_64
$ 

Please advise. Thank You!

I’m CC: @aanand (per @vdemeester - https://github.com/docker/docker/issues/22045#issuecomment-210016484).