Implements hook_archiver_info_alter().
function update_test_archiver_info_alter(&$definitions) {
// We only care about the extensions for now and the only way to add a new
// extension without a class is via alter. This definition is bogus, real
// archivers have a class and the definition goes in the annotation of the
// class.
$definitions['update_test_archiver'] = array(
'extensions' => array(
'update-test-extension',
),
);
}