<!--- 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'
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### 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

```

continue
            with open(b_file_path, 'rb') as file_obj:
                try:
                    info[property_name] = json.loads(to_text(file_obj.read(), errors='surrogate_or_strict'))
                except ValueError:
                    raise AnsibleError("Collection file at '%s' does not contain a valid json string."
                                       % to_native(b_file_path))
        if 'manifest_file' in info:
            manifest = info['manifest_file']['collection_info']
            namespace = manifest['namespace']
            name = manifest['name']
            version = to_text(manifest['version'], errors='surrogate_or_strict')
            if not hasattr(LooseVersion(version), 'version'):
                display.warning("Collection at '%s' does not have a valid version set, falling back to '*'. Found "
                                "version: '%s'" % (to_text(b_path), version))
                version = '*'
            dependencies = manifest['dependencies']
        else:
            display.warning("Collection at '%s' does not have a MANIFEST.json file, cannot detect version."
                            % to_text(b_path))
            parent_dir, name = os.path.split(to_text(b_path, errors='surrogate_or_strict'))
            namespace = os.path.split(parent_dir)[1]
            version = '*'
            dependencies = {}
        meta = CollectionVersionMetadata(namespace, name, version, None, None, dependencies)
        files = info.get('files_file', {}).get('files', {})
        return CollectionRequirement(namespace, name, b_path, None, [version], version, force, parent=parent,
                                     metadata=meta, files=files, skip=True)
    @staticmethod
    def from_name(collection, apis, requirement, force, parent=None):