Move log4j version to properties

Author: MLobo1997

pom.xml

@@ -77,6 +77,7 @@
         <jackson-databind.version>2.6.7</jackson-databind.version>
         <commons-io.version>2.7</commons-io.version>
         <apache.version>1.8</apache.version>
+        <log4j.version>2.14.1</log4j.version>
     </properties>
 
     <dependencyManagement>
@@ -155,7 +156,7 @@
             <dependency>
                 <groupId>org.apache.logging.log4j</groupId>
                 <artifactId>log4j-core</artifactId>
-                <version>2.14.1</version>
+                <version>${log4j.version}</version>
             </dependency>
 
             <!--Testing-->