Merge pull request #9 from Djunnni/dependabot/maven/guestbook/org.springframework-spring-webmvc-5.2.20.RELEASE

Bump spring-webmvc from 4.3.5.RELEASE to 5.2.20.RELEASE in /guestbook

Author: Djunnni

guestbook/pom.xml

@@ -9,7 +9,7 @@
   <url>http://maven.apache.org</url>
   <properties>
   	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-  	<spring.version>4.3.5.RELEASE</spring.version>
+  	<spring.version>5.2.20.RELEASE</spring.version>
   	<jackson2.version> 2.10.2</jackson2.version>
   </properties>