Update Client.php

[sunkaflek]

orderPickup returns a standard json reponse and should not be void.

if it is void, there is no way to tell whether the call has been un/successful and why

[tomas-novotny]

Thank you for reporting this error. Returning status code 200 with an error message is an undocumented API behavior.

Instead of returning response data, you can only validate that it has additional message a throw it as an exception – fixed in 6b683ad.

if it is void, there is no way to tell whether the call has been un/successful and why

If the method doesn't throw an exception, it was successful.

Is this change good enough for you? If so, please close the PR and I will release changes as tag v6.2.0.

[sunkaflek]

If the method doesn't throw an exception, it was successful.

I see now .. sorry I think I have misunderstood the whole thing. I read in the official Balikobot documentation that ORDERPICKUP returns a json with status. When this library's orderPickup returned NULL no matter what data I tried, I got confused and assumed it was a bug, then solved it by returning the response.

Personally I think a response might be clearer and more in line with the docu, but I guess NULL vs Exception also works.

Returning status code 200 with an error message is an undocumented API behavior

This is not what I tried to say, I do not know whether it does that. I meant it returns a json, not NULL, as does this library.

Sorry for the confusion, I'm closing the PR