Bump maven-checkstyle-plugin from 2.17 to 3.1.2

Bumps [maven-checkstyle-plugin](https://github.com/apache/maven-checkstyle-plugin) from 2.17 to 3.1.2.
- [Release notes](https://github.com/apache/maven-checkstyle-plugin/releases)
- [Commits](https://github.com/apache/maven-checkstyle-plugin/compare/maven-checkstyle-plugin-2.17...maven-checkstyle-plugin-3.1.2)

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pom.xml b/pom.xml
index 9994d4a..9d0df41 100644
--- a/pom.xml
+++ b/pom.xml
@@ -244,7 +244,7 @@
     <commons.encoding>UTF-8</commons.encoding>
     <checkstyle.header.file>${basedir}/src/conf/checkstyle-header.txt</checkstyle.header.file>
     <checkstyle.config.file>${basedir}/src/conf/checkstyle.xml</checkstyle.config.file>
-    <checkstyle.version>2.17</checkstyle.version>
+    <checkstyle.version>3.1.2</checkstyle.version>
     <commons.japicmp.version>0.15.2</commons.japicmp.version>
     <commons.jacoco.version>0.8.6</commons.jacoco.version>
     <japicmp.skip>false</japicmp.skip>