<!--- 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

```

if no_deps or len(dependency_map[collection].dependencies) == 0:
                checked_parents.add(collection)
    return dependency_map
def _get_collection_info(dep_map, existing_collections, collection, requirement, source, b_temp_path, apis,
                         validate_certs, force, parent=None):
    dep_msg = ""
    if parent:
        dep_msg = " - as dependency of %s" % parent
    display.vvv("Processing requirement collection '%s'%s" % (to_text(collection), dep_msg))
    b_tar_path = None
    if os.path.isfile(to_bytes(collection, errors='surrogate_or_strict')):
        display.vvvv("Collection requirement '%s' is a tar artifact" % to_text(collection))
        b_tar_path = to_bytes(collection, errors='surrogate_or_strict')
    elif urlparse(collection).scheme.lower() in ['http', 'https']:
        display.vvvv("Collection requirement '%s' is a URL to a tar artifact" % collection)
        try:
            b_tar_path = _download_file(collection, b_temp_path, None, validate_certs)
        except urllib_error.URLError as err:
            raise AnsibleError("Failed to download collection tar from '%s': %s"
                               % (to_native(collection), to_native(err)))
    if b_tar_path:
        req = CollectionRequirement.from_tar(b_tar_path, force, parent=parent)
        collection_name = to_text(req)
        if collection_name in dep_map:
            collection_info = dep_map[collection_name]
            collection_info.add_requirement(None, req.latest_version)
        else:
            collection_info = req
    else:
        validate_collection_name(collection)