upgrade AWS SDK
diff --git a/build.properties b/build.properties
index 164c8f2..5a6dd23 100644
--- a/build.properties
+++ b/build.properties
@@ -1,2 +1,2 @@
 ivy.install.version=2.5.0
-aws.sdk.version=2.17.129
+aws.sdk.version=2.17.155