Create NuGet.config

Add NuGet.config

NuGet.config

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c)  Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information. -->
+
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="myget.org roslyn-master-nightly" value="https://dotnet.myget.org/F/roslyn-master-nightly/api/v3/index.json" />
+    <add key="dotnet.myget.org roslyn-tools" value="https://dotnet.myget.org/F/roslyn-tools/api/v3/index.json" />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+
+  <!-- Don't let user disabled sources in VS prevent us from restoring -->
+  <disabledPackageSources>
+    <clear />
+  </disabledPackageSources>
+</configuration>