
currently an invalid collection will error out on docs sanity, but this is misleading since the problem is that the collection name itself is invalid, a previous test verifying this should be introduced to avoid confusion.

example currently:
```
Running sanity test 'ansible-doc' with Python 3.7
ERROR: Command "ansible-doc -t module cyberark.ansible-security-automation-collection.cyberark_account cyberark.ansible-security-automation-collection.cyberark_authentication cyberark.ansible-security-automation-collection.cyberark_credential cyberark.ansible-security-automation-collection.cyberark_user" returned exit status 250.
>>> Standard Error
[WARNING]: module cyberark.ansible-security-automation-collection.cyberark_account not found in: /dev/null:/home/abehl/work/src/anshul_ansible/ansible/lib/ansible/modules
ERROR! Unexpected Exception, this is probably a bug: cannot unpack non-iterable NoneType object
```
##### ISSUE TYPE
- Feature Idea

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

modern_unit_path = 'tests/unit/'
        modern_unit_path_found = any(path.startswith(modern_unit_path) for path in paths)
        legacy_unit_path = 'tests/units/'  
        legacy_unit_path_found = any(path.startswith(legacy_unit_path) for path in paths)
        if modern_unit_path_found and legacy_unit_path_found:
            messages.warning.append('Ignoring tests in "%s" in favor of "%s".' % (legacy_unit_path, modern_unit_path))
        elif legacy_unit_path_found:
            messages.warning.append('Rename "%s" to "%s" to run unit tests.' % (legacy_unit_path, modern_unit_path))
        elif modern_unit_path_found:
            pass  
        else:
            messages.error.append('Cannot run unit tests without "%s".' % modern_unit_path)