Create a Web Application in Visual Studio and create a Git repository at GitHub
Create a blank repository and Push the code from Visual studio at Git Repository .
Create a Web App on Azure .
Configure Continuous delivery for Web Application.
Click on configure and choose Source code repository
Once you have configured and click on OK it will create a build and a release definition in the VSTS account A new slot created a for testing
It will create a default build and Release definition for building web apps on VSTS
Default Deployment tasks created for Azure Web App deployment
Go to VSTS default release process