kiji-rest: REST-96. Need a Python3 client for KijiREST

issue: https://jira.kiji.org/browse/REST-96
review: https://review.kiji.org/r/1604
commit: https://github.com/kijiproject/kiji-rest/commit/c27737f8b8fce5e7e7c12afa0cde7457aa7075ca