Hm - it looks like Akka's default strategy is to call `Thread.currentThread.getContextClassLoader` for this - it would make sense to have that be our default as well so we know we aren't changing anything wrt how people initialize akka.

https://github.com/akka/akka/blob/master/akka-actor/src/main/scala/akka/actor/ActorSystem.scala#L189