kiji-schema: SCHEMA-798. Delete Tool should not open an instance while deleting it

issue: https://jira.kiji.org/browse/SCHEMA-798
review: https://review.kiji.org/r/1889
commit: https://github.com/kijiproject/kiji-schema/commit/a36bd2d38e1dd67e02e7703e9abeecc7c98dd11a