fix(package): update force-del to version 2.0.0

fix(package): update `has-lockfile` to version 4.0.0 (#64)

* fix(package): update has-lockfile to version 4.0.0

* refactor(API): adopt changes in `has-lockfile` v4

fix(CLI): output in to multiple lines only if more than 1 lockfiles f…

…ound

feat(CLI): Integrate `update-notifier`

perf(API): run `del` only when `git rm` rejected

previously, `del` always got triggered

2.0.3

fix: update dependencies

fix: update dependencies (#39)

test: improve tests

feat(API): run process asynchronously (Promise) (#34)