kiji-checkin: EXP-420. Update to scala 2.10

issue: https://jira.kiji.org/browse/EXP-420
review: https://review.kiji.org/r/1692
commit: https://github.com/kijiproject/kiji-checkin/commit/039365129f2ffd2c23337c61097ceed845320665
kiji-delegation: EXP-420. Update to scala 2.10

issue: https://jira.kiji.org/browse/EXP-420
review: https://review.kiji.org/r/1693
commit: https://github.com/kijiproject/kiji-delegation/commit/a72fc9038298c8fba329dccbea47123b128b6781
kiji-bento: EXP-420. Update to scala 2.10

issue: https://jira.kiji.org/browse/EXP-420
review: https://review.kiji.org/r/1691
commit: https://github.com/kijiproject/kiji-bento/commit/55bcba05910a9d632593f2e833f2003ea318d59c