datastore: unbreak build.

A datastore example test relies on a non-deterministic ordering of Property
fields.

This change disables the Output: line so that this doesn't cause the
build to fail.

Change-Id: I7b2dcd257f35142c99fc489c602a94764e52edf5
Reviewed-on: https://code-review.googlesource.com/7991
Reviewed-by: Dave Day <djd@golang.org>
diff --git a/datastore/example_test.go b/datastore/example_test.go
index 253cc69..570bf26 100644
--- a/datastore/example_test.go
+++ b/datastore/example_test.go
@@ -535,5 +535,5 @@
 		// TODO: Handle error.
 	}
 	fmt.Println(props)
-	// Output: [{User Alice false} {Score 97 false}]
+	// TODO(jba): make this output stable: Output: [{User Alice false} {Score 97 false}]
 }