move some test file to match src code

Just move some test suite to corresponding package

Author: Daoyuan <daoyuan.wang@intel.com>

Closes #1401 from adrian-wang/movetestfiles and squashes the following commits:

d1a6803 [Daoyuan] move some test file to match src code

core/src/test/scala/org/apache/spark/BroadcastSuite.scala → core/src/test/scala/org/apache/spark/broadcast/BroadcastSuite.scala

@@ -15,14 +15,12 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.broadcast
 
+import org.apache.spark.storage.{BroadcastBlockId, _}
+import org.apache.spark.{LocalSparkContext, SparkConf, SparkContext, SparkException}
 import org.scalatest.FunSuite
 
-import org.apache.spark.storage._
-import org.apache.spark.broadcast.{Broadcast, HttpBroadcast}
-import org.apache.spark.storage.BroadcastBlockId
-
 class BroadcastSuite extends FunSuite with LocalSparkContext {
 
   private val httpConf = broadcastConf("HttpBroadcastFactory")

core/src/test/scala/org/apache/spark/ConnectionManagerSuite.scala → core/src/test/scala/org/apache/spark/network/ConnectionManagerSuite.scala

@@ -15,15 +15,14 @@
  * limitations under the License.
  */
 
-package org.apache.spark
-
-import org.scalatest.FunSuite
+package org.apache.spark.network
 
 import java.nio._
 
-import org.apache.spark.network.{ConnectionManager, Message, ConnectionManagerId}
-import scala.concurrent.Await
-import scala.concurrent.TimeoutException
+import org.apache.spark.{SecurityManager, SparkConf}
+import org.scalatest.FunSuite
+
+import scala.concurrent.{Await, TimeoutException}
 import scala.concurrent.duration._
 import scala.language.postfixOps
 

core/src/test/scala/org/apache/spark/PipedRDDSuite.scala → core/src/test/scala/org/apache/spark/rdd/PipedRDDSuite.scala

@@ -15,25 +15,21 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
 import java.io.File
 
-import org.scalatest.FunSuite
-
-import org.apache.spark.rdd.{HadoopRDD, PipedRDD, HadoopPartition}
-import org.apache.hadoop.mapred.{JobConf, TextInputFormat, FileSplit}
 import org.apache.hadoop.fs.Path
+import org.apache.hadoop.io.{LongWritable, Text}
+import org.apache.hadoop.mapred.{FileSplit, JobConf, TextInputFormat}
+import org.apache.spark._
+import org.scalatest.FunSuite
 
 import scala.collection.Map
 import scala.language.postfixOps
 import scala.sys.process._
 import scala.util.Try
 
-import org.apache.hadoop.io.{Text, LongWritable}
-
-import org.apache.spark.executor.TaskMetrics
-
 class PipedRDDSuite extends FunSuite with SharedSparkContext {
 
   test("basic pipe") {

core/src/test/scala/org/apache/spark/ZippedPartitionsSuite.scala → core/src/test/scala/org/apache/spark/rdd/ZippedPartitionsSuite.scala

@@ -15,8 +15,9 @@
  * limitations under the License.
  */
 
-package org.apache.spark
+package org.apache.spark.rdd
 
+import org.apache.spark.SharedSparkContext
 import org.scalatest.FunSuite
 
 object ZippedPartitionsSuite {

core/src/test/scala/org/apache/spark/AkkaUtilsSuite.scala → core/src/test/scala/org/apache/spark/util/AkkaUtilsSuite.scala

@@ -15,14 +15,14 @@
  * limitations under the License.
  */
 
-package org.apache.spark
-
-import org.scalatest.FunSuite
+package org.apache.spark.util
 
 import akka.actor._
+import org.apache.spark._
 import org.apache.spark.scheduler.MapStatus
 import org.apache.spark.storage.BlockManagerId
-import org.apache.spark.util.AkkaUtils
+import org.scalatest.FunSuite
+
 import scala.concurrent.Await
 
 /**