
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

self.__check_test_path(paths, sanity_messages)
        self.__check_test_path(paths, integration_messages)
        self.__check_test_path(paths, unit_messages)
        
        integration_targets_path = self.__check_integration_path(paths, integration_messages)
        self.__check_unit_path(paths, unit_messages)
        return ContentLayout(root,
                             paths,
                             plugin_paths=plugin_paths,
                             collection=CollectionDetail(
                                 name=collection_name,
                                 namespace=collection_namespace,
                                 root=collection_root,
                             ),
                             test_path='tests',
                             results_path='tests/output',
                             sanity_path='tests/sanity',
                             sanity_messages=sanity_messages,
                             integration_path='tests/integration',
                             integration_targets_path=integration_targets_path.rstrip(os.path.sep),
                             integration_vars_path='tests/integration/integration_config.yml',
                             integration_messages=integration_messages,
                             unit_path='tests/unit',
                             unit_module_path='tests/unit/plugins/modules',
                             unit_module_utils_path='tests/unit/plugins/module_utils',
                             unit_messages=unit_messages,
                             )
    @staticmethod
    def __check_test_path(paths, messages):