Create Handler instance
a Handler object
Used for parse R Markdown and lift into command line interface, Dockerfile, Docker container, and cwl json.
dockerfileHandler
a function or NULL, how you handle Dockefile, for example, push it to GitHub.
dockerHandler
a function or NULL, how you handle local docker container, for example, push it to DockerHub.
cwlHandler
a function or NULL, how you handle cwl json file or yaml file, for example, push it to SevenBridges platform as an app.