Avoid adding and committing every file when releasing

[abarmat]

This is a change on the standard behaviour when releasing.

Release by default adds all the files in your local repo and then commit everything, this might cause undesired files to be pushed, a security risk depending on the files exposed.

This change will only commit package.json and package-lock.json as part of the bump version stage.

Closes #162

[fmiras]

cc @leo