Backend upgrade

nicolasstucki · nicolasstucki · commit f02678378f3b · 2017-11-27T10:28:37.000+01:00
diff --git a/scala-backend b/scala-backend
@@ -1 +1 @@
-Subproject commit 31f96813dc8282a685728ae5769f7c1004d89e3a
+Subproject commit b4f91888b6e778fd1ea0aee2dbf832ae8b59a48a
