Buggy behavior related to npm lock files makes the goal of reproducible builds
and hassle-free automated releases nearly impossible to achieve at
present. With npm's lock files disabled we rely on pinned dependencies (exact
versions only in the package.json files of embark and embark-ui) for a
hopefully good result. This is an experiment while the project is in an alpha
release phase, and if problems are experienced we can return to using
npm-shrinkwrap.json / package-lock.json, or we can investigate a transition to
the yarn package manager, for ourselves and possibly for our users too.