update sbt version
diff --git a/project/build.properties b/project/build.properties
index 4c5ee59..d9f279f 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -15,4 +15,4 @@
 # limitations under the license.
 #
 
-sbt.version=1.2.8
+sbt.version=1.3.3