remove mkdirp use

node 10.12 has { recursive: true }

src/routes/test/settings-test.js

@@ -9,7 +9,7 @@ var async = require('async'),
     constants = require('../../constants.js'),
     database = require('../../database.js'),
     expect = require('expect.js'),
-    mkdirp = require('mkdirp'),
+    fs = require('fs'),
     rimraf = require('rimraf'),
     server = require('../../server.js'),
     superagent = require('superagent');
@@ -21,7 +21,7 @@ var BACKUP_FOLDER = '/tmp/backup_test';
 var token = null;
 
 function setup(done) {
-    mkdirp.sync(BACKUP_FOLDER);
+    fs.mkdirSync(BACKUP_FOLDER, { recursive: true });
 
     async.series([
         server.start.bind(null),