move helper script to scripts dir and add one to Makefile

scripts/template/lib/responses.py.j2

@@ -0,0 +1,15 @@
+from __future__ import unicode_literals
+from moto.core.responses import BaseResponse
+from .models import {{ service }}_backends
+
+
+class {{ service_class }}Response(BaseResponse):
+    @property
+    def {{ service }}_backend(self):
+        return {{ service }}_backends[self.region]
+
+    # add methods from here
+
+
+# add teampltes from here
+