Serve error

[MatteoGauthier]

Missing dependencies during serve,

These dependencies were not found:                                                                                                                                                              * vuelidate in ./src/main.js                                                                    * vuelidate/lib/validators in ./node_modules/cache-loader/dist/cjs.js??ref--12-0!./node_modules/
babel-loader/lib!./node_modules/cache-loader/dist/cjs.js??ref--0-0!./node_modules/vue-loader/lib
??vue-loader-options!./src/views/EventCreate.vue?vue&type=script&lang=js&                                                                                                                       To install them, you can run: npm install --save vuelidate vuelidate/lib/validators

[DiveInto]

see https://github.com/Code-Pop/real-world-vue/issues/9