Feature: completing the backend architecture

[thefuadeniola]

I have completed the backend architecture. Added post routes for signup, login and create poll. Get routes to fetch all polls and fetch by ID has also been added. This will make development of frontend easier as routes are now available to make calls to. I have tested the routes with backend and made some test polls in mongodb.

Here is a postman test to fetch all created polls from the database

Please accept this issue and assign to me.

[namansharma3007]

@thefuadeniola done

[thefuadeniola]

Created the PR regarding this!!

[thefuadeniola]

Waiting on you to accept PR, looking to build signup and login pages!!