feat: remove shelljs dependency (tophat#302)

* refactor: remove shelljs dependency

* test: update remove

* test: version in use

* test: which command

* test: missing env path

fix: print versions (tophat#296)

* test: print versions behaviour

* fix: print regular versions

feat: yarn semantic version config (tophat#291)

* feat: add chalk deps

* feat: use chalk for log colors

* feat: get yarn version from pkg json and yarnversion file

* wip: use semver for version matching

* feat: use version matching semver in config

* test: improve which command test

* test: version fns

* test: getsplitversionargs

* test: list remote catch error

feat: 🎸 add commitizen (tophat#295)

BREAKING CHANGE: Bumped node minium node version to 8.0 in previous commit. Minimum node
version is now 8.0

infra: pin version for release

infra: greenkeeper/eslint config prettier 3.5.0 (tophat#288)

* chore(package): update eslint-config-prettier to version 3.5.0

* chore(package): update lockfile yarn.lock

* ignore production modules

test: happy path sanity testing and coverage (tophat#280)

test: happy path sanity testing and coverage

add pull reminders badge (tophat#282)

ci: stop pinning verison (tophat#279)

fix: invalid version number when running yvm use on start (tophat#277)