Ensure directory for test data exists before writing to it.

Author: ahmelsayed

src/WebJobs.Script.WebHost/Extensions/FunctionMetadataExtensions.cs

@@ -121,6 +121,7 @@ private static async Task<string> GetTestData(string testDataPath, ScriptJobHost
         {
             if (!File.Exists(testDataPath))
             {
+                FileUtility.EnsureDirectoryExists(Path.GetDirectoryName(testDataPath));
                 await FileUtility.WriteAsync(testDataPath, string.Empty);
             }