The installation process will create a common.bash file. This file should be the central, canonical authority for management of environment variables. While a subprocess may override them, the files in common.bash should be treated as authoritative defaults. Processes (e.g. `docker build`, `bats`, inside `Jenkinsfile`) can read this file and process the results therein.
You should edit this file to change the image name, and add any other helpful environment variables.
This will also install a Jenkinsfile to your repository, if it doesn't have one. This will ensure that your Jenkins pipeline can leverage these scripts in the way intended. Ensuring the commands that you issue on your laptop match the commands issued by the build pipeline is critical to ensure predictable, reliable results.