Upgrade akka 2.4.7
Upgrade akka 2.4.7

ryez/gatling,GabrielPlassard/gatling,GabrielPlassard/gatling,GabrielPlassard/gatling,GabrielPlassard/gatling,thkluge/gatling,ryez/gatling,thkluge/gatling,thkluge/gatling,ryez/gatling,thkluge/gatling,ryez/gatling