use logback for logging in tests

core/src/test/resources/logback.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <logger name="akka.event" level="WARN"/>
+
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <withJansi>true</withJansi>
+        <encoder>
+            <pattern>%date %-35(%highlight(%-5level) %logger{0}) %msg%n</pattern>
+        </encoder>
+    </appender>
+
+
+    <root level="DEBUG">
+        <appender-ref ref="STDOUT"/>
+    </root>
+</configuration>

core/src/test/resources/reference.conf

@@ -1,8 +1,11 @@
 akka {
   extensions = ["com.github.levkhomich.akka.tracing.TracingExtension"]
 
+  loggers = ["akka.event.slf4j.Slf4jLogger"]
   loggers += "com.github.levkhomich.akka.tracing.TracingLogger"
 
+  loglevel = "DEBUG"
+
 #  actor.default-mailbox {
 #    mailbox-type = "com.github.levkhomich.akka.tracing.TracingUnboundedMailbox"
 #  }

project/Build.scala

@@ -217,6 +217,8 @@ object Dependencies {
     val playTest     = "com.typesafe.play" %% "play-test"           % PlayVersion % "test"
     val akkaTest     = "com.typesafe.akka" %% "akka-testkit"        % AkkaVersion % "test"
     val akkaRemote   = "com.typesafe.akka" %% "akka-remote"         % AkkaVersion % "test"
+    val akkaSlf4j    = "com.typesafe.akka" %% "akka-slf4j"          % AkkaVersion % "test"
+    val logback      = "ch.qos.logback"    % "logback-classic"      % "1.1.3"     % "test"
   }
 
   val akka = Seq(Compile.akkaActor, Compile.akkaAgent, Compile.akkaStream, Compile.config)
@@ -231,5 +233,5 @@ object Dependencies {
 
   def test(scalaVersion: String): Seq[ModuleID] =
     Seq(Test.specs, Test.finagle, Test.playTest, Test.akkaTest,
-      Test.akkaRemote, Test.sprayTestkit(scalaVersion))
+      Test.akkaRemote, Test.sprayTestkit(scalaVersion), Test.akkaSlf4j, Test.logback)
 }