Using PHP, design a function that given a Roman numeral in input, is able to compute the modern Hindu-Arabic numeral system representation (aka, 0123456789). For example: Input Output IV MCMXC 1990 Be sure to add all the necessary checks and at least one testing function. Try to split the logic in small functions. What is a "check"? If you have a function that accepts an input, you want to check if such input falls in the right boundary or, in case of loosely typed languages such as PHP, if belongs to the right type. You need to check whether order of letters is correct or not. For example, C character before M does not work. Example: function test(nr) if (nr