feat: promises rewrite and drop support for node 10

[erunion]

Late 2019 in rdme we lost the ability to bundle in $ref pointers spread across multiple files, and unfortunately with the way that that library is written it's difficult to use oas-normalize because it's currently based on supplying callbacks. On top of that, the swagger-parser and swagger2openapi dependencies that oas-normalize have also been rewritten to support promises, leaving this thing in the dust.

So I've fully rewritten it to be promise-based. And added full unit test coverage in the process. And removed a handful of dependencies that it didn't really need.

🚀

🧰 What's being changed?

• 🆕  Full rewrite of the library to be promise-based.
• 🆕  Full test coverage.
• 🧹  Pruning back unnecessary dependencies.
• 💀  Drops support for Node 10.

[kanadgupta]

Just did a pass and changes seem sound! I don't know much about this library and if anything, I'm just weary of all the different ways an OAS file could be invalid lol. Seeing the increase in test coverage is reassuring though!

Also one general question: should all the fixtures you created here exist in @readme/oas-examples? Or are you limiting that library to only valid files?

[kanadgupta]

omfg lol

[erunion]

I've been getting pinged by Dependabot about this every month when it tries to update it. 😅

[kanadgupta]

hell yeah

[erunion]

Also one general question: should all the fixtures you created here exist in @readme/oas-examples? Or are you limiting that library to only valid files?

Yeah that library should only have valid examples.