message: fix: use greenkeeper-lockfile@2
diff: @@ -17,7 +17,7 @@ if [[ ! -z "$GIT_EMAIL" ]] & [[ ! -z "$GIT_USERNAME" ]]; then
  fi
  if [[ ! -x "$(command -v greenkeeper-lockfile-update)" ]]; then
  - yarn global add greenkeeper-lockfile@1
  + yarn global add greenkeeper-lockfile@2
  fi
  greenkeeper-lockfile-update
  