Added checkstyle

.settings.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
   ~ /*
-  ~  * Copyright 2015 the original author or authors.
+  ~  * Copyright 2015-2019 the original author or authors.
   ~  *
   ~  * Licensed under the Apache License, Version 2.0 (the "License");
   ~  * you may not use this file except in compliance with the License.
@@ -34,7 +34,9 @@
 				this settings file, or copy the profile into their ~/.m2/settings.xml.
 			-->
 			<id>spring</id>
-			<activation><activeByDefault>true</activeByDefault></activation>
+			<activation>
+				<activeByDefault>true</activeByDefault>
+			</activation>
 			<repositories>
 				<repository>
 					<id>spring-snapshots</id>