Clear feeds (#131)

eng/Versions.props

@@ -21,7 +21,8 @@
   <PropertyGroup>
     <RestoreSources>
       $(RestoreSources);
-      https://dotnet.myget.org/F/symreader-native/api/v3/index.json
+      https://dotnet.myget.org/F/symreader-native/api/v3/index.json;
+      https://dotnet.myget.org/F/dotnet-core/api/v3/index.json
     </RestoreSources>
   </PropertyGroup>
 </Project>

nuget.config

@@ -2,6 +2,7 @@
 <configuration>
   <!-- Only specify feed for RepoToolset SDK (see https://github.com/Microsoft/msbuild/issues/2982) -->
   <packageSources>
+    <clear />
     <add key="roslyn-tools" value="https://dotnet.myget.org/F/roslyn-tools/api/v3/index.json" />
   </packageSources>
 </configuration>