ec2 module "unsupported parameter for module: volumes"

Ansible 1.7.2, If I follow the example that include module, I am getting:

    msg: unsupported parameter for module: volumes

It works with the devel (future 1.8), but what it puzzles me that it's in the
documentation as available since 1.5, and I can see the option in the
cloud/ec2 file. Is this a bug?

Does this occur even with --check? I just tried ansible-1.7.2 with
the following playbook and --check and it completed fine.

$ cat player.yml
- hosts: localhost
  tasks:
    - ec2:
        key_name: mykey
        group: webserver
        instance_type: m1.large
        image: ami-6e649707
        wait: yes
        wait_timeout: 500
        volumes:
        - device_name: /dev/sdb
          snapshot: snap-abcdef12
          device_type: io1
          iops: 1000
          volume_size: 100
          delete_on_termination: true
        monitoring: yes

$ ansible-playbook --check player.yml

PLAY [localhost] **************************************************************

GATHERING FACTS ***************************************************************
ok: [localhost]

TASK: [ec2 ] ******************************************************************
skipping: [localhost]

PLAY RECAP ********************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=0

So there might be something else going on in your site.
-Toshio