kiji-express-music: EXP-440. Update express music tutorial to use the latest kiji-schema.

issue: https://jira.kiji.org/browse/EXP-440
review: https://review.kiji.org/r/1847
commit: https://github.com/kijiproject/kiji-express-music/commit/ac72d50d5b800445273b6e2517a2cbea356ecad8