Update flow version

Author: zoewangg

pom.xml

@@ -80,7 +80,7 @@
     </scm>
     <properties>
         <awsjavasdk.version>${project.version}</awsjavasdk.version>
-        <flow.version>1.1</flow.version>
+        <flow.version>1.7</flow.version>
         <jackson.version>2.9.6</jackson.version>
         <ion.java.version>1.2.0</ion.java.version>
         <commons.lang.version>3.4</commons.lang.version>