3.1: Carousel basic example
===========================
**Primary Actor**: User

**Scope**: Ngx-bootstrap DEMO / BS version 3&4

**Goal**: Show user basic carousel functionality

Main success scenario:
----------------------
1. User open Carousel demo page
2. User clicks on Basic sub-menu
3. User see carousel component with 3 slides and 2 arrows: left, right
4. When the user clicks on the left arrow - the previous slide has shown
5. When the user clicks on the right arrow - next slide has shown
6. When the user does nothing more than 5 sec - next slide automatically has shown

Variations:
-----------
2*. User scroll to Basic sub-menu