
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

"""
        Return a list of collection layouts, one for each collection in the same collection root as the current collection layout.
        An empty list is returned if the current content layout is not a collection layout.
        """
        layout = self.content
        collection = layout.collection
        if not collection:
            return []
        root_path = os.path.join(collection.root, 'ansible_collections')
        display.info('Scanning collection root: %s' % root_path, verbosity=1)
        namespace_names = sorted(name for name in os.listdir(root_path) if os.path.isdir(os.path.join(root_path, name)))
        collections = []
        for namespace_name in namespace_names:
            namespace_path = os.path.join(root_path, namespace_name)
            collection_names = sorted(name for name in os.listdir(namespace_path) if os.path.isdir(os.path.join(namespace_path, name)))
            for collection_name in collection_names:
                collection_path = os.path.join(namespace_path, collection_name)
                if collection_path == os.path.join(collection.root, collection.directory):
                    collection_layout = layout
                else:
                    collection_layout = self.__create_content_layout(self.__layout_providers, self.__source_providers, collection_path, False)
                file_count = len(collection_layout.all_files())
                if not file_count:
                    continue
                display.info('Including collection: %s (%d files)' % (collection_layout.collection.full_name, file_count), verbosity=1)
                collections.append(collection_layout)
        return collections
    @staticmethod
    def __create_content_layout(layout_providers,