Adds the task_2 back to dataset example (#204)

README.md

@@ -139,6 +139,7 @@ producer_dag:
       bash_command: "echo 1"
       outlets: [ 's3://bucket_example/raw/dataset1.json' ]
       operator: airflow.operators.bash_operator.BashOperator
+    task_2:
       bash_command: "echo 2"
       dependencies: [ task_1 ]
       outlets: [ 's3://bucket_example/raw/dataset2.json' ]