Boolean representation on GuzzleHttp\Psr7\build_query()

[ackintosh]

$data = [
    'true' => true,
    'false' => false
];

/*
 * GuzzleHttp\Psr7\build_query()
 */
var_dump(GuzzleHttp\Psr7\build_query($data));
// string(13) "true=1&false="

/*
 * \http_build_query()
 */
var_dump(\http_build_query($data));
// string(14) "true=1&false=0"

GuzzleHttp\Psr7\build_query() resolves false to '' but I think it should be 0 as well as \http_build_query().

I'll file a PR if it's reasonable for you too.

[pierrre]

FYI this code is called by swagger-codegen.
All code generated by swagger-codegen is broken currently.