<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
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##### SUMMARY
<!--- Explain the problem briefly below -->
We publish semver collection (vyos.vyos:0.0.1-dev58) to ansible galaxy, however by default it seems ansible-galaxy client will not be able to find it. You must specific the version number directly to fetch it.

https://galaxy.ansible.com/vyos/vyos


EDIT:

This is working as expect, but it would be nice to Include:

   --pre                       Include pre-release and development versions. By default, ansible-galaxy only finds stable versions.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
ansible-galaxy

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.9.1
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```


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

<!--- Paste example playbooks or commands between quotes below -->
```yaml
$ ansible-galaxy collection install vyos.vyos -p /tmp/11123
[WARNING]: The specified collections path '/tmp/11123' is not part of the configured Ansible collections paths '/home/pabelanger/.ansible/collections:/usr/share/ansible/collections'. The
installed collection won't be picked up in an Ansible run.

Process install dependency map
ERROR! Cannot meet requirement * for dependency vyos.vyos from source 'https://galaxy.ansible.com/api/'. Available versions before last requirement added: 
Requirements from:
	base - 'vyos.vyos:*'
(venv) [pabelanger@localhost openstack]$ ansible-galaxy collection install vyos.vyos:0.0.1-dev57 -p /tmp/11123
[WARNING]: The specified collections path '/tmp/11123' is not part of the configured Ansible collections paths '/home/pabelanger/.ansible/collections:/usr/share/ansible/collections'. The
installed collection won't be picked up in an Ansible run.

Process install dependency map
Starting collection install process
Installing 'vyos.vyos:0.0.1-dev57' to '/tmp/11123/ansible_collections/vyos/vyos'
```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
vyos.vyos collection to be found and installed

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below

```

galaxy_type = 'collection' if parser.metavar == 'COLLECTION_ACTION' else 'role'
        args_kwargs = {}
        if galaxy_type == 'collection':
            args_kwargs['help'] = 'The collection(s) name or path/url to a tar.gz collection artifact. This is ' \
                                  'mutually exclusive with --requirements-file.'
            ignore_errors_help = 'Ignore errors during installation and continue with the next specified ' \
                                 'collection. This will not ignore dependency conflict errors.'
        else:
            args_kwargs['help'] = 'Role name, URL or tar file'
            ignore_errors_help = 'Ignore errors and continue with the next specified role.'
        install_parser = parser.add_parser('install', parents=parents,
                                           help='Install {0}(s) from file(s), URL(s) or Ansible '
                                                'Galaxy'.format(galaxy_type))
        install_parser.set_defaults(func=self.execute_install)
        install_parser.add_argument('args', metavar='{0}_name'.format(galaxy_type), nargs='*', **args_kwargs)
        install_parser.add_argument('-i', '--ignore-errors', dest='ignore_errors', action='store_true', default=False,
                                    help=ignore_errors_help)
        install_exclusive = install_parser.add_mutually_exclusive_group()
        install_exclusive.add_argument('-n', '--no-deps', dest='no_deps', action='store_true', default=False,
                                       help="Don't download {0}s listed as dependencies.".format(galaxy_type))
        install_exclusive.add_argument('--force-with-deps', dest='force_with_deps', action='store_true', default=False,
                                       help="Force overwriting an existing {0} and its "
                                            "dependencies.".format(galaxy_type))
        if galaxy_type == 'collection':
            install_parser.add_argument('-p', '--collections-path', dest='collections_path',
                                        default=C.COLLECTIONS_PATHS[0],
                                        help='The path to the directory containing your collections.')
            install_parser.add_argument('-r', '--requirements-file', dest='requirements',