Apache Airflow version: 1.10.15

Kubernetes version (if you are using kubernetes) (use kubectl version):
`Client Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.6", GitCommit:"96fac5cd13a5dc064f7d9f4f23030a6aeface6cc", GitTreeState:"clean", BuildDate:"2019-08-19T11:13:49Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Majo

Is your feature request related to a problem? Please describe.

As a user, I can attach comments to nodes that describe its purpose.

Elyra currently does not pass through this information to the target environment (Kubeflow Pipelines and Apache Airflow), even though it might

Summary

The current implementation does not allow creating templates specifying the parallelism field as per the Argo spec.

Use Cases

Many possible use cases, my current one is limiting the amount of parallel nodes running a certain template so as to save

Currently the env variables injected are specific to this docker image https://github.com/barney-s/docker-airflow

Align it with https://github.com/puckel/docker-airflow and make necessary changes in the operator to make it work with both.

related to GoogleCloudPlatform/airflow-operator#10