cant get log4j to run in play! framework 2.2.1 (scala project)

I cant get log4j to run in play framework 2.2.1

I use the following log4j.properties:

log4j.rootLogger=INFO
log4j.logger.deng=INFO
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n

application.conf:

application.log=INFO
application.log.path=/log4j.properties

scala usage example:

object SomeService {

  private val log = Logger.getLogger(this.getClass())

  def someMethod() = {
      log.error("test")
  }
}

If I run a test I get the following console output:

log4j:WARN No appenders could be found for logger (SomeService.class).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Can someone help me with this please?

Thanks a lot