Adding Microsoft.CSharp

Author: fabiocav

src/WebJobs.Script/Description/CSharp/FunctionMetadataResolver.cs

@@ -36,6 +36,7 @@ public sealed class FunctionMetadataResolver : MetadataReferenceResolver
                 "System.Core",
                 "System.Xml",
                 "System.Net.Http",
+                "Microsoft.CSharp",
                 typeof(object).Assembly.Location,
                 typeof(IAsyncCollector<>).Assembly.Location, /*Microsoft.Azure.WebJobs*/
                 typeof(JobHost).Assembly.Location, /*Microsoft.Azure.WebJobs.Host*/