From the JEP draft which I'm working on:

The testing of what composes "Jenkins Essentials" is the subject of another JEP
document, but in the context of the Evergreen packaging there are no plans for
specific test suites other than to ensure that the `jenkins/evergreen`
container can properly boot both Jenkins core and the `evergreen-client` after
a new `jenkins/evergreen` image has been built.

This task is to implement that basic smoke testing of the container after it has been built.