section 7 of course: https://www.udemy.com/the-complete-nodejs-developer-course-2/learn/v4/t/lecture/5795054?start=0
how to start mongodb server C:\Program Files\MongoDB\Server\3.4\bin>mongod --dbpath C://Users/dms3/Dropbox/testnode/udemy_20171127/node-todo-api-mongo/mongo-data
C:\Program Files\MongoDB\Server\3.4\bin>mongod --dbpath C://Users/dms3/Documents/testnode/udemy_20171127/ToDo-Api-Mongo/mongo-data