[MINOR] Update sample notebook with Spark 2.x APIs
[MINOR] Update sample notebook with Spark 2.x APIs

apache/incubator-toree,lresende/incubator-toree,hmost1/incubator-toree,lresende/incubator-toree,hmost1/incubator-toree,lresende/incubator-toree,hmost1/incubator-toree,apache/incubator-toree,lresende/incubator-toree,hmost1/incubator-toree,apache/incubator-toree