Add a dummy class in the serializer-deserializer-msk-iam module for j…

…avadoc and source jar generation (#256)

serializer-deserializer-msk-iam/src/main/java/com/amazonaws/services/schemaregistry/Dummy.java

@@ -0,0 +1,7 @@
+package com.amazonaws.services.schemaregistry;
+
+/**
+ * This is just a dummy file created so the Javadoc jar and Source jar will be successfully generated for release
+ * */
+public class Dummy {
+}