#970 single logging framework should be enforced (#982)

* #496 Add pipeline module to parent pom ✨

* #496: Add main application class and test for pipeline

* #496: Checkstyle format and add log messages on pipeline stages 🎨

* #496: Fill readme sections of pipeline ✨

* #496: Javadocs and checkstyle formatting 🎨

* #496: Follow PMD checks and add more explanation as block comment on App.java

* #496: Apply requested PR changes by iluwatar 🎨

* #970: Replace log4j usage on commander pattern to Slf4j API 🎨

* #970: Replace log4j usage on dao pattern to Slf4j API 🎨

* #970: Replace log4j usage on data mapper pattern to Slf4j API 🎨

* #970: Remove log4j dependency on data transfer object pom 🔥

* #970: Replace log4j usage on module pattern to Slf4j API 🎨

* #970: Replace log4j usage on serverless pattern to Slf4j API 🎨

This also removes the aws log4j dependency

* #970: Remove unnecessary gitignore line for log4j.xml 🔥

* #970: Remove remaining remnants of log4j 🔥

* #970: Replace System.out logging with appropriate logging methods 🎨

* #970: Replace System.out method references to Logger::info 🎨

event-queue/src/main/java/com/iluwatar/event/queue/App.java

@@ -22,6 +22,9 @@
  */
 package com.iluwatar.event.queue;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
@@ -39,6 +42,8 @@ import javax.sound.sampled.UnsupportedAudioFileException;
  * items from the queue at a later time.
  */
 public class App {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
   /**
    * Program entry point.
    * 
@@ -51,7 +56,7 @@ public class App {
     audio.playSound(audio.getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
     audio.playSound(audio.getAudioStream("./etc/Closed-Hi-Hat-1.wav"), -8.0f);
     
-    System.out.println("Press Enter key to stop the program...");
+    LOGGER.info("Press Enter key to stop the program...");
     try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
       br.read();
     }