replace unicode arrows

* ⇒, →, ←
* because we don't want to show them in documentation snippets and
  then it's complicated to avoid that when snippets are
  located in src/test/scala in individual modules
* dont replace object `→` in FSM.scala and PersistentFSM.scala

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemotingMultiNodeSpec.scala

@@ -32,7 +32,7 @@ abstract class RemotingMultiNodeSpec(config: MultiNodeConfig) extends MultiNodeS
   with STMultiNodeSpec
   with FlightRecordingSupport
   with ImplicitSender
-  with DefaultTimeout { self: MultiNodeSpec ⇒
+  with DefaultTimeout { self: MultiNodeSpec =>
 
   // Keep track of failure so we can print artery flight recording on failure
   private var failed = false