kiji-schema-shell: EXP-420. Update to scala 2.10

issue: https://jira.kiji.org/browse/EXP-420
review: https://review.kiji.org/r/1707
commit: https://github.com/kijiproject/kiji-schema-shell/commit/50a1b21f54f3a8b75b6ced6db0266a18977d0128