Artifactory cannot proxy a Bintray NPM repository.
1. Create an open source NPM repo on Bintray
2. Upload an NPM package to it
3. Follow the "Set me Up" instructions to configure the NPM client for the Bintray Repo
4. Download the uploaded package (notice it succeeds)
5. Run 'npm cache clear' to remove the package
6. Point Artifactory to the Bintray repo (https://api.bintray.com/npm/<org|user>/<repo>)
7. Follow the Artifatory "Set me up instructions"
8. Attempt to download the package
9. Observe success in download metadata but failure to download the actual package (tgz)
Notice the request is made to api.bintray.com but the JSON tells us to download from dl.bintray.com: