Merge pull request #1 from sriramjv1219/Authentication_Service_Implementation

Sidebar changes and fixed lint errors.

minor side bar updates: removed unnecessary list items.

Minor updates to login component.

Handled negative authentication scenerios.

Added progress bar while authenticating.

Integrated with Login API

Initial Commit with base code for integrating Authentication API.

Login page: Modified to use username instead of email id and removed Email validation.

Implemented Auth guards.

Removed warning to refer to background image for authentication module in scss file - postcss.

Added Login screen to authentication module, set login screen as start up page and changed favicon.

Added authentication module and Lazy loading Authentication.

Initial commit with basic shell

Initial commit