Add config entry for tests monitoring

Use jest for tests monitoring.

package.json

@@ -6,7 +6,8 @@
   "main": "app.js",
   "scripts":{
     "start": "node app.js",
-    "test": "jest"
+    "test": "jest",
+    "test:watch": "jest --watch"
   },
   "dependencies":{
     "webdriverio": "4.7.1",