scrabble-score: replace illegal word

multibillionaire can't be played as a word in a real scrabble game.

scrabble-score/src/test/java/ScrabbleScoreTest.java

                 {"f", 4},
                 {"street", 6},
                 {"quirky", 22},
-                {"MULTIBILLIONAIRE", 20},
+                {"oxyphenbutazone", 41},
                 {"alacrity", 13},
         });
     }