Remove backupDone from storage interface

This is only used by caas

src/storage/gcs.js

@@ -9,8 +9,6 @@ exports = module.exports = {
     remove: remove,
     removeDir: removeDir,
 
-    backupDone: backupDone,
-
     testConfig: testConfig,
 
     // Used to mock GCS
@@ -315,11 +313,3 @@ function testConfig(apiConfig, callback) {
     });
 }
 
-function backupDone(apiConfig, backupId, appBackupIds, callback) {
-    assert.strictEqual(typeof apiConfig, 'object');
-    assert.strictEqual(typeof backupId, 'string');
-    assert(Array.isArray(appBackupIds));
-    assert.strictEqual(typeof callback, 'function');
-
-    callback();
-}