Exclude slf4j->log4j bridge

- Projects which use scalatest-embedded-kafka may have their own slf4j bindings which can conflict with these

Author: kciesielski

build.sbt

@@ -1,5 +1,8 @@
 import sbtrelease.Version
 
+val slf4jLog4jOrg = "org.slf4j"
+val slf4jLog4jArtifact = "slf4j-log4j12"
+
 lazy val commonSettings = Seq(
   name := "scalatest-embedded-kafka",
   organization := "net.manub",
@@ -8,10 +11,9 @@ lazy val commonSettings = Seq(
   parallelExecution in Test := false,
   libraryDependencies ++= Seq(
     "org.scalatest" %% "scalatest" % "2.2.5",
-    "org.apache.kafka" %% "kafka" % "0.9.0.1",
-    "org.apache.zookeeper" % "zookeeper" % "3.4.7",
-    "org.apache.avro" % "avro" % "1.7.7",
-    "org.slf4j" % "log4j-over-slf4j" % "1.7.12",
+    "org.apache.kafka" %% "kafka" % "0.9.0.1" exclude(slf4jLog4jOrg, slf4jLog4jArtifact),
+    "org.apache.zookeeper" % "zookeeper" % "3.4.7" exclude(slf4jLog4jOrg, slf4jLog4jArtifact),
+    "org.apache.avro" % "avro" % "1.7.7" exclude(slf4jLog4jOrg, slf4jLog4jArtifact),
     "com.typesafe.akka" %% "akka-actor" % "2.3.14" % Test,
     "com.typesafe.akka" %% "akka-testkit" % "2.3.14" % Test
   )