Fix deprecation warning: "Calling promisify on a function that returns a Promise is likely a mistake"

[gzurbach]

Fixes #462

I tested this change locally in my project and it seems to work fine. However, I am not familiar enough with the codebase to understand potential side-effects with other configurations.

[titanism]

Not merging since some consolidate exposed functions are sync or callback and need to be converted as such. Instead, a eslint code comment should be added to ignore this rule/deprecation notice.

[almeidx]

Not merging since some consolidate exposed functions are sync or callback and need to be converted as such. Instead, a eslint code comment should be added to ignore this rule/deprecation notice.

It's not a warning from ESLint. This is a warning shown during runtime (from a Node.js built-in function).
And since this is a deprecation warning, this should be addressed, even if not in the way that it was done in this pull request