nullpointer fix for multiple toJson calls on one serializer instance

Change-Id: Ibc6153b82348fa43814a30af49a85162ac7febfa
diff --git a/pom.xml b/pom.xml
index 8f8a82d..7f7f2d4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -72,7 +72,8 @@
     <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
-      <version>0.11.8</version>
+      <version>1.16.6</version>
+        <scope>provided</scope>
     </dependency>
     <dependency>
       <groupId>log4j</groupId>