header names are supposed to be case insensitive

[maciakm]

right now the headers validation is case sensitive.
that includes security validation of http "Authentication" header
This makes it hard to use this library with frameworks like symfony that casts all header names to lowercase.

related RFC:
https://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2

[maciakm]

when I submitted this I already saw the resolution :)
it is not in this library responsibility to handle the case (in)sensitivity of headers.
I switched to ServerRequestImplementation that handles it properly and openapi-psr7-validator works as it should.

closing