SPARK-1806 (addendum) Use non-deprecated methods in Mesos 0.18

The update to Mesos 0.18 caused some deprecation warnings in the build. The change to the non-deprecated version is straightforward as it emulates what the Mesos driver does with the deprecated method anyway (https://github.com/apache/mesos/blob/c5aa1dd22155d79c5a7c33076319299a40fd63b3/src/sched/sched.cpp#L1354)

Author: Sean Owen <sowen@cloudera.com>

Closes #920 from srowen/SPARK-1806 and squashes the following commits:

8d76b6a [Sean Owen] Use non-deprecated methods in Mesos 0.18

core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala

@@ -207,10 +207,12 @@ private[spark] class CoarseMesosSchedulerBackend(
             .addResources(createResource("cpus", cpusToUse))
             .addResources(createResource("mem", sc.executorMemory))
             .build()
-          d.launchTasks(offer.getId, Collections.singletonList(task), filters)
+          d.launchTasks(
+            Collections.singleton(offer.getId),  Collections.singletonList(task), filters)
         } else {
           // Filter it out
-          d.launchTasks(offer.getId, Collections.emptyList[MesosTaskInfo](), filters)
+          d.launchTasks(
+            Collections.singleton(offer.getId), Collections.emptyList[MesosTaskInfo](), filters)
         }
       }
     }

core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosSchedulerBackend.scala

@@ -223,7 +223,7 @@ private[spark] class MesosSchedulerBackend(
         // Reply to the offers
         val filters = Filters.newBuilder().setRefuseSeconds(1).build() // TODO: lower timeout?
         for (i <- 0 until offers.size) {
-          d.launchTasks(offers(i).getId, mesosTasks(i), filters)
+          d.launchTasks(Collections.singleton(offers(i).getId), mesosTasks(i), filters)
         }
       }
     } finally {