Unwanted files are committed to the repository

Unwanted files are committed to a repository after updating Lerna to version 3.22.0 (which contains the change added in https://github.com/lerna/lerna/pull/2445).

At least this change does not feel like a minor one, it definitely should be explicitly documented, not only in that PR description.

Expected Behavior

If temporary files are generated during build, they should not be committed back to the repository. At least this beahviour should not be default, but rather enabled with a switch.

Current Behavior

All untracked files are committed by default.

Possible Solution

Gitignore all the stuff would work, but it should not be.

Steps to Reproduce (for bugs)

1. Introduce changes to a package.
2. Generate some secrets and/or trash.
3. Publish new version with Lerna
4. All the secrets and trash are committed to the repository

Your Environment

Executable	Version
lerna --version	3.22.0

[evocateur]

Released as v3.22.1. Thanks all for your patience.

[fubar]

@evocateur to extend on this, the suggestions to explicitly exclude files in .gitignore are impractical and outright unrealistic. They would require any and every file that could possibly be created or moved to the working directory knowingly or unknowingly by me or by any program that I run to be added to .gitignore, or else they WILL get published without prompt for review or confirmation. The lack of sensitivity to the severity of this issue is very surprising to me. People have their private credentials published without their knowledge as we speak.