pin version of node-fetch and add end-to-end test to catch breaking changes

[gr2m]

This is in response to node-fetch/node-fetch#1300

[eamodio]

Will this be moving to node-fetch 3? Or pinning v2? Hoping for the former. 😄

[gr2m]

We’ll probably do both for some time, as we transition to ESM

[github-actions]

🎉 This issue has been resolved in version 7.0.0-beta.2 🎉

The release is available on:

• GitHub release
• npm package (@beta dist-tag)

Your semantic-release bot 📦🚀

[gr2m]

We’ll probably do both for some time, as we transition to ESM

we ended up removing the dependency on node-fetch altogether via #432. It will be part of the v7 release. You can pass a custom fetch implementation e.g. for older Node versions or for mocking with https://github.com/wheresrhys/fetch-mock