scrabble-score: replace 'multibillionaire' with 'oxyphenbutazone'

[kytrinyx]

The word multibillionaire is too long for the scrabble board. Oxyphenbutazone, on the other hand, is legal.

Please verify that there is no test for multibillionaire in the scrabble-score in this track. If the word is included in the test data, then it should be replaced with oxyphenbutazone. Remember to check the case (if the original is uppercase, then the replacement also should be).

If multibillionaire isn't used, then this issue can safely be closed.

See exercism/problem-specifications#86

[ricemery]

This is a problem with the Scala Unit test. I will make the change.