<!--- 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

```

remove_parser = parser.add_parser('remove', parents=parents, help='Delete roles from roles_path.')
        remove_parser.set_defaults(func=self.execute_remove)
        remove_parser.add_argument('args', help='Role(s)', metavar='role', nargs='+')
    def add_delete_options(self, parser, parents=None):
        delete_parser = parser.add_parser('delete', parents=parents,
                                          help='Removes the role from Galaxy. It does not remove or alter the actual '
                                               'GitHub repository.')
        delete_parser.set_defaults(func=self.execute_delete)
    def add_list_options(self, parser, parents=None):
        galaxy_type = 'role'
        if parser.metavar == 'COLLECTION_ACTION':
            galaxy_type = 'collection'
        list_parser = parser.add_parser('list', parents=parents,
                                        help='Show the name and version of each {0} installed in the {0}s_path.'.format(galaxy_type))
        list_parser.set_defaults(func=self.execute_list)
        list_parser.add_argument(galaxy_type, help=galaxy_type.capitalize(), nargs='?', metavar=galaxy_type)
    def add_search_options(self, parser, parents=None):
        search_parser = parser.add_parser('search', parents=parents,
                                          help='Search the Galaxy database by tags, platforms, author and multiple '
                                               'keywords.')
        search_parser.set_defaults(func=self.execute_search)
        search_parser.add_argument('--platforms', dest='platforms', help='list of OS platforms to filter by')
        search_parser.add_argument('--galaxy-tags', dest='galaxy_tags', help='list of galaxy tags to filter by')
        search_parser.add_argument('--author', dest='author', help='GitHub username')
        search_parser.add_argument('args', help='Search terms', metavar='searchterm', nargs='*')
    def add_import_options(self, parser, parents=None):