* #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 🎨
* Made minor changes in some patterns such as removed throws clause where not needed, changed incorrect order of arguments in assertEquals
* Minor refactorings and code style changes. 1) Removed several use of raw types 2) Removed unnecessary throws clauses 3) Used lambda expressions wherever applicable 4) Used apt assertion methods for readability 5) Use of try with resources wherever applicable 6) Corrected incorrect order of assertXXX arguments
* Removed unused import from Promise
* Addressed review comments
* Addressed checkstyle issue
