LIVY-225. Fix two issues running integration test with Spark 2.0.

1. Create a dummy jar to let Spark yarn#client correctly launch the application.
2. Since `SQLContext` is deprecated in Spark 2.0, so additional information will be printed out when creating. Changing the regex pattern.

Closes apache#213

integration-test/src/main/scala/com/cloudera/livy/test/framework/MiniCluster.scala

@@ -19,6 +19,7 @@
 package com.cloudera.livy.test.framework
 
 import java.io._
+import java.nio.file.{Files, Paths}
 import javax.servlet.http.HttpServletResponse
 
 import scala.concurrent.duration._
@@ -230,9 +231,14 @@ class MiniCluster(config: Map[String, String]) extends Cluster with MiniClusterU
 
     // When running a real Spark cluster, don't set the classpath.
     val extraCp = if (!isRealSpark()) {
+      val dummyJar = Files.createTempFile(Paths.get(tempDir.toURI), "dummy", "jar").toFile
       Map(
         SparkLauncher.DRIVER_EXTRA_CLASSPATH -> childClasspath,
-        SparkLauncher.EXECUTOR_EXTRA_CLASSPATH -> childClasspath)
+        SparkLauncher.EXECUTOR_EXTRA_CLASSPATH -> childClasspath,
+        // Used for Spark 2.0. Spark 2.0 will upload specified jars to distributed cache in yarn
+        // mode, if not specified it will check jars folder. Here since jars folder is not
+        // existed, so it will throw exception.
+        "spark.yarn.jars" -> dummyJar.getAbsolutePath)
     } else {
       Map()
     }

integration-test/src/test/scala/com/cloudera/livy/test/InteractiveIT.scala

@@ -37,8 +37,8 @@ class InteractiveIT extends BaseIntegrationTestSuite {
       s.run("""sc.getConf.get("spark.executor.instances")""").verifyResult("res1: String = 1")
       s.run("sqlContext").verifyResult(startsWith("res2: org.apache.spark.sql.hive.HiveContext"))
       s.run("val sql = new org.apache.spark.sql.SQLContext(sc)").verifyResult(
-        startsWith("sql: org.apache.spark.sql.SQLContext = org.apache.spark.sql.SQLContext"))
-
+        ".*" + Pattern.quote(
+        "sql: org.apache.spark.sql.SQLContext = org.apache.spark.sql.SQLContext") + ".*")
       s.run("abcde").verifyError(evalue = ".*?:[0-9]+: error: not found: value abcde.*")
       s.run("throw new IllegalStateException()")
         .verifyError(evalue = ".*java\\.lang\\.IllegalStateException.*")