Update NuGet.config to reference the azureadwebstacknightly feed and remove aspnetcore-dev

Author: kevinchalet

NuGet.config

@@ -2,8 +2,8 @@
 <configuration>
   <packageSources>
     <add key="NuGet" value="https://api.nuget.org/v3/index.json" />
-    <add key="aspnetcore" value="https://dotnet.myget.org/F/aspnetcore-dev/api/v3/index.json" />
     <add key="aspnetkatana" value="https://dotnet.myget.org/F/katana-dev/api/v3/index.json" />
     <add key="aspnet-contrib" value="https://www.myget.org/F/aspnet-contrib/api/v3/index.json" />
+    <add key="azureadwebstacknightly" value="https://www.myget.org/F/azureadwebstacknightly/api/v3/index.json" />
   </packageSources>
 </configuration>