The demo scripts in `src/test/cli_shim`, while very useful when developing the
shim, were never fully completed and are not part of embark's CI, so remove
them. A future cross-platform test suite of the shim should be written in the
usual way (with TS/JS) instead of using bash scripts running in a Docker
container.
yarn.lock files are generated for embark and embark-ui, and their package.json
files and other npm related files are updated to support and require using yarn
for development of embark itself and for embark's CI.
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.