Make matcher(...) return nothing when no match is found

[frankier]

There is an error due to not being able to convert nothing into FileType.Type otherwise in the case of no match.

[frankier]

@Agent-Hellboy Would it be possible to merge this? Anything else needed?

[Agent-Hellboy]

Hi @frankier , please fix the failed unittests. Where are you using this library, which use case are you targeting?
We also need to update the package in the Julia registry. I stopped using Julia after college. I will do it on the weekend.

[frankier]

Whoops. Fixed. Looks like I pushed something different to what I tested locally and then had blindness to the "nightly" CI run which is often flakey.

[frankier]

For use in https://github.com/JuliaPsychometricsBazaar/RDataGet.jl to replicate R's data loading behaviour which will sniff for compressed files, ignoring the extension.

[Agent-Hellboy]

Thank you, I will release a new version over the weekend.