Removing the nuget.config and have build.props mention the nuget package sources. (dotnet#38)

* Added sequential grouping of columns

* removed nuget.config and have only props mentions the nuget sources

* reverted the file

Author: srsaggam

Directory.Build.props

@@ -18,6 +18,7 @@
       https://api.nuget.org/v3/index.json;
       https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json;
       https://dotnet.myget.org/F/dotnet-core/api/v3/index.json;
+      https://dotnet.myget.org/F/system-commandline/api/v3/index.json;
     </RestoreSources>
   </PropertyGroup>