Create data folder in Dockerfile

Change-Id: If65e2fabe73eb85f5d53bca50986d159b4710583
diff --git a/Dockerfile b/Dockerfile
index 2426f5d..c8be9df 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -78,6 +78,8 @@
 
 USER kalamar
 
+RUN mkdir /kalamar/data
+
 ENV MOJO_PORT   64543
 ENV MOJO_LISTEN http://*:${MOJO_PORT}
 ENV MOJO_MODE   production