Docker build, run and push task plugin for GoCD

We can use a Dockerfile to build an image and tag it.

If needed, we can run a script against the built image.

Use case - build and test the application in the container environment in which it will actually run.

During run, the entire working directory is mounted as volume into the container, and the specified script (along with the optional arguments) is run in the container.

If needed, we can push the built image to Dockerhub.

It is possible to optionally choose any one or a combination of these.

• Support private registry
• More options while running, like setting specific environment variables