Removed io.spray spray-json dependency as it is not needed.

core/src/main/scala/spark/deploy/JsonProtocol.scala

 package spark.deploy
 
 import master.{JobInfo, WorkerInfo}
-import spray.json._
+import cc.spray.json._
 
 /**
  * spray-json helper class containing implicit conversion to json for marshalling responses
  */
 private[spark] object JsonProtocol extends DefaultJsonProtocol {
-  import cc.spray.json._
-
   implicit object WorkerInfoJsonFormat extends RootJsonWriter[WorkerInfo] {
     def write(obj: WorkerInfo) = JsObject(
       "id" -> JsString(obj.id),

project/SparkBuild.scala

@@ -134,7 +134,6 @@ object SparkBuild extends Build {
       "cc.spray" % "spray-can" % "1.0-M2.1",
       "cc.spray" % "spray-server" % "1.0-M2.1",
       "cc.spray" %%  "spray-json" % "1.1.1",
-      "io.spray" %%  "spray-json" % "1.2.3",
       "org.apache.mesos" % "mesos" % "0.9.0-incubating"
     ) ++ (if (HADOOP_MAJOR_VERSION == "2") Some("org.apache.hadoop" % "hadoop-client" % HADOOP_VERSION) else None).toSeq,
     unmanagedSourceDirectories in Compile <+= baseDirectory{ _ / ("src/hadoop" + HADOOP_MAJOR_VERSION + "/scala") }