* Additional release script options for publishing canary versions
- `branch` specifies a branch other than master
- `local` skips pulling from the remote branch and checking CircleCI
- `tag` specifies an npm dist tag other than `latest` or `next`
We may add a higher-level `canary` option in the future.
* Address Brian's feedback:
- Updated description of `local` option
- Throws if the `latest` tag is specified for a prerelease version
* Move build/packages/* to build/node_modules/*
This fixes Node resolution in that folder and lets us require() packages in it in Node shell for manual testing.
* Link fixtures to packages/node_modules
This updates the location and also uses link: instead of file: to avoid Yarn caching the folder contents.
