Ignore errors from `npm ls` in build.js
Ignore errors from `npm ls` in build.js

`npm ls` fails if some peerDependencies are not installed
Since `showWebDependencies()` function is for debug purposes only, we catch possible promise reject of `npm()` and convert it into Promise.resolve() that it always succeeds. We do something similar in the CircleCI config with the `true` in `npm list --depth=1 || true`.
phovea/generator-phovea,phovea/generator-phovea,phovea/generator-phovea,phovea/generator-phovea,phovea/generator-phovea