feature/login-backend

[robbdouglas]

• [x] SECRETKEY in .env
• [x] install cookie-parser (middleware)
• [x] install cors
• [x] edit server.js
• [x] edit usersRoutes
• [x] edit usersControllers

[robbdouglas]

• [x] add login to usersControllers

[robbdouglas]

• [x] add cors and cookie-parser to server.js

[robbdouglas]

• [x] add middleware to log the method and path of each request, and the body of POST requests

[robbdouglas]

• [x] edit and correct login in usersControllers
• [x] test with insomnia