title: Build separately a web app backend in a Xamarin solution using VSTS
body: <p>Got a Xamarin solution which includes a project for a web app backend.
  Trying to set up a separate build definition for the web app backend so that it deploys to Azure app service. We have that API app folder inside the Xamarin solution folder.</p>
  
  <p>When trying manual mapping to build the web app it fails as it tries to build the whole solution while it should only build that project as I used MSBuild task and pointed it to the csproj file in that folder.</p>
  
  <p>How can we get that specific folder to build separately?</p>