[CB-3380] Updates scripts to work better with Node dependency
- check_reqs now completes preliminary work in bash/batch ensuring
  completion without node installed
- create now calls npm install first

Revewied by Bryan Higgins <bhiggins@blackberry.com>
[CB-3497] Fix create script for Linux/OSX

- NPM install will return error code 0 if run successfuly

Reviewed by Hasan Ahmad <haahmad@blackberry.com>