##### SUMMARY
ansible_run_tags documentation says the default is empty ("[]") at https://docs.ansible.com/ansible/latest/reference_appendices/config.html#tags-run

However when running a debug print with no tags specified, we get this output:

```
- name: print tags
  debug:
    msg: "{{ ansible_run_tags }}"
```

```
$ ansible-playbook deploy.yml
```

```

TASK [workstation : print tags] ************************************************************************************************************************************************************************************************************************************************************
task path: /home/gdevenyi/projects/lozano_ansible/roles/workstation/tasks/main.yml:4
ok: [192.168.56.104] => {
    "msg": [
        "all"
    ]
}

```

<!--- HINT: Did you know the documentation has an "Edit on GitHub" link on every page ? -->

##### ISSUE TYPE
- Documentation Report

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

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.9
```

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

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. OS version, browser, etc. -->
Ubuntu 18.04
##### ADDITIONAL INFORMATION
<!--- Describe how this improves the documentation, e.g. before/after situation or screenshots -->

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

''' check for conflicting options '''
        if fork_opts:
            if op.forks < 1:
                self.parser.error("The number of processes (--forks) must be >= 1")
        return op
    @abstractmethod
    def init_parser(self, usage="", desc=None, epilog=None):
        """
        Create an options parser for most ansible scripts
        Subclasses need to implement this method.  They will usually call the base class's
        init_parser to create a basic version and then add their own options on top of that.
        An implementation will look something like this::
            def init_parser(self):
                super(MyCLI, self).init_parser(usage="My Ansible CLI", inventory_opts=True)
                ansible.arguments.option_helpers.add_runas_options(self.parser)
                self.parser.add_option('--my-option', dest='my_option', action='store')
        """
        self.parser = opt_help.create_base_parser(os.path.basename(self.args[0]), usage=usage, desc=desc, epilog=epilog, )
    @abstractmethod
    def post_process_args(self, options):