Fixies for running with artifactory 4.14.1

[rogeriochaves]

Summary

This will help solving #521

I use a private NPM registry hosted via Artifactory v4.14.1 and I was having some issues.

The first one is that apparently this version of Artifactory still does not support the application/vnd.npm.install-v1+json header implemented on #3112. To fix that, I noted by reading npm docs that we can add a fallback to application/json.

This allowed yarn to correctly download metadata from artifactory. Then, I had another problem, with the isRequestToRegistry function implemented on #2598. The problem was that although I do specify https://myartifactory for my registy, some dependencies gets the https replaced with http by yarn, preventing it from sending the authentication header. I don't know why this happens, maybe its artifactory itself telling yarn to use http (I've noted it happens on public dependencies)

So, I've modified the function isRequestToRegistry to understand that https://myartifactory and http://myartifactory is still the same registry.

Test plan

I've added extra test cases to isRequestToRegistry functional test, maybe some snapshots testing needs to be changed for the vnd.npm header, but they gave no errors on my machine.

Cheers!

[tuto]

we need this in our team 💃
very useful and necesary

Thank you very much Rogerio

[rogeriochaves]

@Daniel15 @bestander @kittens could you review this PR? We really need this

[joyarzun]

Wowwww finally, thanks @bestander and @rogeriochaves

[Daniel15]

Thanks for the pull request! If you want to use this today (before a new stable/RC release comes out), you can grab a nightly build: https://yarnpkg.com/en/docs/nightly