added upgrade script
diff --git a/Makefile b/Makefile
index a49be94..267bc10 100644
--- a/Makefile
+++ b/Makefile
@@ -31,9 +31,10 @@
 SQL_INSTALL = sql/$(EXTENSION)--$(EXTVERSION).sql
 DATA = $(SQL_INSTALL) \
   sql/datasketches--1.3.0--1.4.0.sql \
+  sql/datasketches--1.3.0--1.6.0.sql \
   sql/datasketches--1.4.0--1.5.0.sql \
   sql/datasketches--1.5.0--1.6.0.sql \
-  sql/datasketches--1.3.0--1.6.0.sql
+  sql/datasketches--1.6.0--1.7.0.sql
 
 EXTRA_CLEAN = $(SQL_INSTALL)