Update equalsverifier version to 3.19.4 (#219)

revert to 3.19.4 to support Jave8

Author: gkorland

pom.xml

@@ -96,7 +96,7 @@
 		<dependency>
 			<groupId>nl.jqno.equalsverifier</groupId>
 			<artifactId>equalsverifier</artifactId>
-			<version>4.3</version>
+			<version>3.19.4</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>