SchemaIncompleteException: No schema for composer_manager.settings

I believe that https://www.drupal.org/node/2391795 is now causing issues when trying to run tests, see below:

    Drupal\Core\Config\Schema\SchemaIncompleteException: No schema for
    composer_manager.settings in
    Drupal\Core\Config\Testing\ConfigSchemaChecker->onConfigSave() (line 91
    of
    /home/josh/web/develfix/core/lib/Drupal/Core/Config/Testing/ConfigSchemaChecker.php).
    Drupal\Core\Config\Testing\ConfigSchemaChecker->onConfigSave(Object,
    'config.save', Object)
    Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('config.save',
    Object)
    Drupal\Core\Config\Config->save()
    Drupal\Core\Config\ConfigInstaller->createConfiguration('', Array)
    Drupal\Core\Config\ConfigInstaller->installDefaultConfig('module',
    'composer_manager')
    Drupal\Core\Extension\ModuleInstaller->install(Array, 1)
    Drupal\simpletest\WebTestBase->setUp()
    Drupal\commerce\Tests\CommerceTestBase->setUp()
    Drupal\commerce\Tests\CommerceStoreCRUDTest->setUp()
    Drupal\simpletest\TestBase->run(Array)
    simpletest_script_run_one_test('28',
    'Drupal\commerce\Tests\CommerceStoreCRUDTest')