Merge pull request #25 from apache/dependabot/maven/org.apache.maven.plugins-maven-checkstyle-plugin-3.1.1

Bump maven-checkstyle-plugin from 2.7 to 3.1.1
diff --git a/pom.xml b/pom.xml
index 7d80021..612171e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -374,7 +374,7 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-checkstyle-plugin</artifactId>
-            <version>2.7</version>
+            <version>3.1.1</version>
             <configuration>
               <configLocation>config/maven_checks.xml</configLocation>
               <headerLocation>config/maven-header.txt</headerLocation>