##### SUMMARY
Unable to use the mount mode :nocopy on volume 

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
docker_container

##### ANSIBLE VERSION
```
ansible 2.8.1
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /var/lib/awx/venv/venv-Ansible-28-python27/lib/python2.7/site-packages/ansible
  executable location = /var/lib/awx/venv/venv-Ansible-28-python27/bin/ansible
  python version = 2.7.5 (default, Jun 20 2019, 20:27:34) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```
N/A
```

##### OS / ENVIRONMENT
AWX 3.0/docker 1.13/ RHEL7.4


##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: start nexus_ihm services
  docker_container:
    name: nexus_ihm
    image: '{{ docker_images.nexus_ihm.image }}:{{ docker_images.nexus_ihm.version }}'
    state: started
    recreate: yes
    log_driver: json-file
    restart_policy: 'unless-stopped'
    hostname: nexus_ihm
    env:
      TZ: Europe/Paris
    volumes:
      - 'nfsdata:/nexus-data:nocopy'
      - 'nfsbackup:/backup'
```
##### EXPECTED RESULTS
Beeing able to access the volume within the container like in :  

```sh
[root@LX01665L ~]# docker run --rm -ti -v nfsdata:/test --name test alpine /bin/sh
/ # ls /test/
config.json  init-stdin   init-stdout
/ # exit
[root@LX01665L ~]# docker run --rm -ti -v nfsdata:/test:nocopy --name test alpine /bin/sh
/ # ls /test/
backup               etc                  kar                  port
blobs                generated-bundles    keystores            restore-from-backup
cache                health-check         lock                 tmp
db                   instances            log                  upgrades
elasticsearch        javaprefs            orient
/ #
```

##### ACTUAL RESULTS
The task crash with (NB, accordingly to the documentation in https://docs.ansible.com/ansible/latest/modules/docker_container_module.html where it's not specified beeing usable ) : 

```
fatal: [lx01665l.tb.uro.equant.com]: FAILED! => {"changed": false, "msg": "Found invalid volumes mode: nocopy"}
```

if key_main is None:
                    if key_main in all_options:
                        self.fail("The module option '%s' cannot be specified in the comparisons dict, "
                                  "since it does not correspond to container's state!" % key)
                    self.fail("Unknown module option '%s' in comparisons dict!" % key)
                if key_main in comp_aliases_used:
                    self.fail("Both '%s' and '%s' (aliases of %s) are specified in comparisons dict!" % (key, comp_aliases_used[key_main], key_main))
                comp_aliases_used[key_main] = key
                
                if value in ('strict', 'ignore'):
                    comparisons[key_main]['comparison'] = value
                elif value == 'allow_more_present':
                    if comparisons[key_main]['type'] == 'value':
                        self.fail("Option '%s' is a value and not a set/list/dict, so its comparison cannot be %s" % (key, value))
                    comparisons[key_main]['comparison'] = value
                else:
                    self.fail("Unknown comparison mode '%s'!" % value)
        
        comparisons['publish_all_ports'] = dict(type='value', comparison='strict', name='published_ports')
        comparisons['expected_ports'] = dict(type='dict', comparison=comparisons['published_ports']['comparison'], name='expected_ports')
        comparisons['disable_healthcheck'] = dict(type='value',
                                                  comparison='ignore' if comparisons['healthcheck']['comparison'] == 'ignore' else 'strict',
                                                  name='disable_healthcheck')
        
        if self.module.params['ignore_image'] and comparisons['image']['comparison'] != 'ignore':
            self.module.warn('The ignore_image option has been overridden by the comparisons option!')
        if self.module.params['purge_networks'] and comparisons['networks']['comparison'] != 'strict':
            self.module.warn('The purge_networks option has been overridden by the comparisons option!')
        self.comparisons = comparisons
    def _get_additional_minimal_versions(self):