add shuffle.py into run-tests

Author: davies

python/run-tests

@@ -61,6 +61,7 @@ run_test "pyspark/broadcast.py"
 run_test "pyspark/accumulators.py"
 run_test "pyspark/serializers.py"
 unset PYSPARK_DOC_TEST
+run_test "pyspark/shuffle.py"
 run_test "pyspark/tests.py"
 run_test "pyspark/mllib/_common.py"
 run_test "pyspark/mllib/classification.py"