add package

src/main/scala/com/aliyun/odps/spark/examples/makedata_recsys/video_dssm_sampler.scala

@@ -1,3 +1,4 @@
+package com.aliyun.odps.spark.examples.makedata_recsys
 import org.apache.spark.sql.{DataFrame, SparkSession, Row}
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.types._