Add format to backupsdb

Call remove/removeDir based on the format

src/storage/noop.js

@@ -7,6 +7,7 @@ exports = module.exports = {
     copy: copy,
 
     remove: remove,
+    removeDir: removeDir,
 
     backupDone: backupDone,
 
@@ -59,12 +60,22 @@ function copy(apiConfig, oldFilePath, newFilePath, callback) {
     callback();
 }
 
-function remove(apiConfig, pathPrefix, callback) {
+function remove(apiConfig, filename, callback) {
+    assert.strictEqual(typeof apiConfig, 'object');
+    assert.strictEqual(typeof filename, 'string');
+    assert.strictEqual(typeof callback, 'function');
+
+    debug('remove: %s', filename);
+
+    callback();
+}
+
+function removeDir(apiConfig, pathPrefix, callback) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof pathPrefix, 'string');
     assert.strictEqual(typeof callback, 'function');
 
-    debug('remove: %s', pathPrefix);
+    debug('removeDir: %s', pathPrefix);
 
     callback();
 }