Invalid json strings are parsed successfully

[zephyr111]

The library accept invalid json strings. Here is the code to reproduce the issue:

subroutine test_parsing()
    type(fson_value), pointer :: jsonValue
    jsonValue => fson_parse(str=' [ - 4 y 2 ] ') ! invalid json, but works fine !
    call fson_destroy(jsonValue)
end subroutine