Checklist

• I have ensured my pull request is not behind the main or master branch of the original repository.
• I have rebased all commits where necessary so that reviewing this pull request can be done without having to merge it first.
• I have written a commit message that passes commitlint linting.
• I have ensured that my code changes pass linting tests.
• I have ensured that my code changes pass unit tests.
• I have described my pull request and the reasons for code changes along with context if necessary.

Description

fs-promise is deprecated and since Node v10.X, there is a built-in fs/promises module (also available with the .promises property) for promise-based file system APIs.

This removes fs-promise and uses the built-in module that is available.

• Closes Javascript qstn #147 (spam)