Deploy images previously shipped node_modules and the bundled task code
in a single layer, so every deploy re-pushed and re-pulled the full
dependency tree even when nothing in it changed. The generated
Containerfile now copies `/app/node_modules` as its own layer and the
app files separately. With unchanged dependencies the dependency layer
is identical across deploys, so registries and workers already have it
and only the code layer moves.
Saadi Myftija
bd8ce4a50f