[SPARK-7989] [SPARK-10651] [CORE] [TESTS] Increase timeout to fix flaky tests

I noticed only one block manager registered with master in an unsuccessful build (https://amplab.cs.berkeley.edu/jenkins/job/Spark-Master-SBT/AMPLAB_JENKINS_BUILD_PROFILE=hadoop2.2,label=spark-test/3534/)
```
15/09/16 13:02:30.981 pool-1-thread-1-ScalaTest-running-BroadcastSuite INFO SparkContext: Running Spark version 1.6.0-SNAPSHOT
...
15/09/16 13:02:38.133 sparkDriver-akka.actor.default-dispatcher-19 INFO BlockManagerMasterEndpoint: Registering block manager localhost:48196 with 530.3 MB RAM, BlockManagerId(0, localhost, 48196)
```
In addition, the first block manager needed 7+ seconds to start. But the test expected 2 block managers so it failed.

However, there was no exception in this log file. So I checked a successful build (https://amplab.cs.berkeley.edu/jenkins/job/Spark-Master-SBT/3536/AMPLAB_JENKINS_BUILD_PROFILE=hadoop2.2,label=spark-test/) and it needed 4-5 seconds to set up the local cluster:
```
15/09/16 18:11:27.738 sparkWorker1-akka.actor.default-dispatcher-5 INFO Worker: Running Spark version 1.6.0-SNAPSHOT
...
15/09/16 18:11:30.838 sparkDriver-akka.actor.default-dispatcher-20 INFO BlockManagerMasterEndpoint: Registering block manager localhost:54202 with 530.3 MB RAM, BlockManagerId(1, localhost, 54202)
15/09/16 18:11:32.112 sparkDriver-akka.actor.default-dispatcher-20 INFO BlockManagerMasterEndpoint: Registering block manager localhost:32955 with 530.3 MB RAM, BlockManagerId(0, localhost, 32955)
```
In this build, the first block manager needed only 3+ seconds to start.

Comparing these two builds, I guess it's possible that the local cluster in `BroadcastSuite` cannot be ready in 10 seconds if the Jenkins worker is busy. So I just increased the timeout to 60 seconds to see if this can fix the issue.

Author: zsxwing <zsxwing@gmail.com>

Closes #8813 from zsxwing/fix-BroadcastSuite.

core/src/test/scala/org/apache/spark/ExternalShuffleServiceSuite.scala

@@ -61,7 +61,7 @@ class ExternalShuffleServiceSuite extends ShuffleSuite with BeforeAndAfterAll {
     // local blocks from the local BlockManager and won't send requests to ExternalShuffleService.
     // In this case, we won't receive FetchFailed. And it will make this test fail.
     // Therefore, we should wait until all slaves are up
-    sc.jobProgressListener.waitUntilExecutorsUp(2, 10000)
+    sc.jobProgressListener.waitUntilExecutorsUp(2, 60000)
 
     val rdd = sc.parallelize(0 until 1000, 10).map(i => (i, 1)).reduceByKey(_ + _)
 

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

@@ -311,7 +311,7 @@ class BroadcastSuite extends SparkFunSuite with LocalSparkContext {
         new SparkContext("local-cluster[%d, 1, 1024]".format(numSlaves), "test", broadcastConf)
       // Wait until all salves are up
       try {
-        _sc.jobProgressListener.waitUntilExecutorsUp(numSlaves, 10000)
+        _sc.jobProgressListener.waitUntilExecutorsUp(numSlaves, 60000)
         _sc
       } catch {
         case e: Throwable =>

core/src/test/scala/org/apache/spark/scheduler/SparkListenerWithClusterSuite.scala

@@ -43,7 +43,7 @@ class SparkListenerWithClusterSuite extends SparkFunSuite with LocalSparkContext
 
     // This test will check if the number of executors received by "SparkListener" is same as the
     // number of all executors, so we need to wait until all executors are up
-    sc.jobProgressListener.waitUntilExecutorsUp(2, 10000)
+    sc.jobProgressListener.waitUntilExecutorsUp(2, 60000)
 
     val rdd1 = sc.parallelize(1 to 100, 4)
     val rdd2 = rdd1.map(_.toString)