Upgrade to Dropwizard Metrics 3.1.5

Closes gh-9463

spring-boot-dependencies/pom.xml

@@ -68,7 +68,7 @@
 		<crashub.version>1.3.2</crashub.version>
 		<derby.version>10.13.1.1</derby.version>
 		<dom4j.version>1.6.1</dom4j.version>
-		<dropwizard-metrics.version>3.1.4</dropwizard-metrics.version>
+		<dropwizard-metrics.version>3.1.5</dropwizard-metrics.version>
 		<ehcache.version>2.10.4</ehcache.version>
 		<ehcache3.version>3.2.2</ehcache3.version>
 		<embedded-mongo.version>1.50.5</embedded-mongo.version>