Bump maven-checkstyle-plugin from 3.0.0 to 3.1.2 (#28)

Bumps [maven-checkstyle-plugin](https://github.com/apache/maven-checkstyle-plugin) from 3.0.0 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-3.0.0...maven-checkstyle-plugin-3.1.2)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
diff --git a/pom.xml b/pom.xml
index a722d47..ae3af97 100644
--- a/pom.xml
+++ b/pom.xml
@@ -156,7 +156,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-checkstyle-plugin</artifactId>
-                <version>3.0.0</version>
+                <version>3.1.2</version>
                 <configuration>
                     <configLocation>${buildtools.dir}/wss4j-checkstyle.xml</configLocation>
                     <includeTestSourceDirectory>false</includeTestSourceDirectory>