Begin implementation of CheckStyle style checking

By: md_5 <git@md-5.net>

paper-api/src/test/java/org/bukkit/plugin/TestPlugin.java

@@ -13,7 +13,7 @@ import org.bukkit.generator.ChunkGenerator;
 public class TestPlugin extends PluginBase {
     private boolean enabled = true;
 
-    final private String pluginName;
+    private final String pluginName;
 
     public TestPlugin(String pluginName) {
         this.pluginName = pluginName;