Include error stacktrace in copyright plugin

Signed-off-by: Jorge Bescos Gascon <jorge.bescos.gascon@oracle.com>

Author: jbescos

etc/travis/travis.sh

@@ -28,7 +28,7 @@ PING_LOOP_PID=$!
 mvn -version
 
 if [ "$1" = "glassfish-copyright:check" ]; then
-    mvn $1
+    mvn -e $1
 else
     mvn -e -U -B clean install $1 >> $BUILD_OUTPUT 2>&1
 fi