<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### 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

```

elif not collections and not requirements_file:
                raise AnsibleError("You must specify a collection name or a requirements file.")
            if requirements_file:
                requirements_file = GalaxyCLI._resolve_path(requirements_file)
            requirements = self._require_one_of_collections_requirements(collections, requirements_file)
            output_path = GalaxyCLI._resolve_path(output_path)
            collections_path = C.COLLECTIONS_PATHS
            if len([p for p in collections_path if p.startswith(output_path)]) == 0:
                display.warning("The specified collections path '%s' is not part of the configured Ansible "
                                "collections paths '%s'. The installed collection won't be picked up in an Ansible "
                                "run." % (to_text(output_path), to_text(":".join(collections_path))))
            output_path = validate_collection_path(output_path)
            b_output_path = to_bytes(output_path, errors='surrogate_or_strict')
            if not os.path.exists(b_output_path):
                os.makedirs(b_output_path)
            install_collections(requirements, output_path, self.api_servers, (not ignore_certs), ignore_errors,
                                no_deps, force, force_deps)
            return 0
        role_file = context.CLIARGS['role_file']
        if not context.CLIARGS['args'] and role_file is None:
            
            raise AnsibleOptionsError("- you must specify a user/role name or a roles file")
        no_deps = context.CLIARGS['no_deps']
        force_deps = context.CLIARGS['force_with_deps']
        force = context.CLIARGS['force'] or force_deps
        roles_left = []
        if role_file:
            if not (role_file.endswith('.yaml') or role_file.endswith('.yml')):
                raise AnsibleError("Invalid role requirements file, it must end with a .yml or .yaml extension")
            roles_left = self._parse_requirements_file(role_file)['roles']