Enhance e2e tests : use cypress

[licarth]

From @licarth on August 6, 2018 8:2

Currently, our e2e tests are minimalistic. A POST request with cURL against the backend to check that we are able to create a user. See https://github.com/Opla/backend/blob/master/myke.yml#L51

To make this more reliable, we could use some more evolved tools to check user scenarii directly from the frontend.

Example of scenario :

• create a new user
• login
• create an intent
• check that bot's reply is respecting the intent
• publish the bot
• try it

Copied from original issue: Opla/front#283

[licarth]

Note to self : Could use Cypress.