As a user of docker.WithRun, I Should Be Able To specify command arguments for the Docker run So That I Can provide arguments to containers that are meant to be run like commands (e.g have custom entrypoints defined).

== Acceptance Criteria ==
Given I run a docker container
When I run the Groovy syntax of docker.image(busybox).withRun(args: "-v /tmp:/tmp", command: "ls -la /tmp")
Then I expect the underlying docker run command to look like the following "docker run -d -v /tmp:/tmp busybox ls -la /tmp"

=== Notes ====
Expand arguments to https://github.com/jenkinsci/docker-workflow-plugin/blob/153c70d5e863eb499b49d08d6992f3eff3ca586a/src/main/resources/org/jenkinsci/plugins/docker/workflow/Docker.groovy#L133 to allow "command" optional argument as well.