Fixed imagedata snippet (#780)

* fixed snippets

* Fix snippet

Author: JRAlexander

machine-learning/tutorials/TransferLearningTF/ImageData.cs

@@ -12,5 +12,5 @@ public class ImageData
         [LoadColumn(1)]
         public string Label;
     }
-    // <SnippetDeclareTypes>
+    // </SnippetDeclareTypes>
 }