[Sprint #5] Refactoring Users apps

#### Summary
i have refactored `users` app. including more eloquent ways dealing with django Class-Based View. also have changed urls. including appropriate test cases.

#### How View and Controller name changed :
- `listAllView` -> `index`
- `listOneView` -> `show`
- using `users` as namespace.

#### How urls changed :
- `/users/home` : removed
- `/users/list` -> `/users` : user index view ( show all users )
- `/users/:id` : user show view ( show one users )