Support custom headers

[glenthomas]

Is your feature request related to a problem? Please describe.

My web app requires a custom header for authentication.

Describe the solution you'd like

A header input, like this: --header "x-my-header=a-value"

Describe alternatives you've considered

Not sure if there are any alternatives.

Additional context

N/A

[jaimeiniesta]

I would also like to have support for custom headers as I think it would be a flexible way to allow authentication.

I read all the issues requesting support for HTTP Basic Auth and I see that currently the only accepted way is passing the credentials in the URL, but passing them as request headers would be more secure as that's less prone to appear in server logs.

Still, this should be discouraged or disabled in the public validator server, but it would be great to have this option when running our own validator server.

[jaimeiniesta]

Is there a way to disable the logs, or filtering out the credentials part in the URLs?