[Feature Request] Support for Bearer Auth

[ignisanulum]

Would it be possible to add an additional authentication type "Bearer"? This would allow us accessing OAuth 2.0-protected resources by the use of a static API token.

I assume this would be fairly simple (following the mockup by @hunsbea) as only the HTTP auth header would need to be changed from Authorization: Basic $base64string to Authorization: Bearer $token, compared to Basic auth.

This probably also relates to this request as Prometheus (or for that purpose, any other monitoring system) is often secured by some form of token based auth if deployed on Kubernetes.

[HenriWahl]

This sounds interesting.

Right now we are preparing the latest stable release 3.10 - this feature could go into the next testing. If you provide a pull request, this might come to 3.10 already.

[HenriWahl]

Closed due to merge of #858