Minor fixes as reported by CodeClimate

src/test/java/tools/docs/translations/TranslationPageGenerator.java

@@ -20,7 +20,8 @@ import static com.google.common.base.MoreObjects.firstNonNull;
 public class TranslationPageGenerator implements AutoToolTask {
 
     private static final String DOCS_PAGE = ToolsConstants.DOCS_FOLDER + "translations.md";
-    private static final String TEMPLATE_FILE = ToolsConstants.TOOLS_SOURCE_ROOT + "docs/translations/translations.tpl.md";
+    private static final String TEMPLATE_FILE =
+        ToolsConstants.TOOLS_SOURCE_ROOT + "docs/translations/translations.tpl.md";
     private static final Map<String, String> LANGUAGE_NAMES = buildLanguageNames();
 
     // Color configuration for the bars shown next to translation percentage

src/test/java/tools/messages/MessageFileVerifier.java

@@ -70,6 +70,10 @@ public class MessageFileVerifier {
         return !missingKeys.isEmpty() || !missingTags.isEmpty() || !unknownKeys.isEmpty();
     }
 
+    /**
+     * Performs the actual verification for the given file and collects all found issues into this
+     * instance's fields.
+     */
     private void verifyKeys() {
         FileConfiguration configuration = YamlConfiguration.loadConfiguration(messagesFile);
 

src/test/java/tools/utils/TagReplacer.java

@@ -18,7 +18,7 @@ import java.util.regex.Pattern;
  *                       version (in case the page is viewed on a fork)</li>
  * </ul>
  */
-public class TagReplacer {
+public final class TagReplacer {
 
     private TagReplacer() {
     }

src/test/java/tools/utils/TagValueHolder.java

@@ -6,7 +6,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 
-public class TagValueHolder {
+public final class TagValueHolder {
 
     private Map<String, TagValue<?>> values;