Upgrade to Gson 2.8.1

Closes gh-9459

spring-boot-dependencies/pom.xml

@@ -79,7 +79,7 @@
 		<glassfish-el.version>3.0.0</glassfish-el.version>
 		<gradle.version>2.9</gradle.version>
 		<groovy.version>2.4.11</groovy.version>
-		<gson.version>2.8.0</gson.version>
+		<gson.version>2.8.1</gson.version>
 		<h2.version>1.4.195</h2.version>
 		<hamcrest.version>1.3</hamcrest.version>
 		<hazelcast.version>3.7.7</hazelcast.version>