roman-numerals: update tests

exercises/roman-numerals/.meta/version

+1.0.0

exercises/roman-numerals/src/test/java/RomanNumeralsTest.java

     @Parameters(name = "{index}: expected arabic numeral {0} to be converted to roman numeral \"{1}\".")
     public static Collection<Object[]> data() {
         return Arrays.asList(new Object[][]{
-                {0, ""},
                 {1, "I"},
                 {2, "II"},
                 {3, "III"},