kiji-mapreduce: KIJIMR-291.  Remove profile for building Cassandra version of KijiMR.

issue: https://jira.kiji.org/browse/KIJIMR-291
review: https://review.kiji.org/r/2036
commit: https://github.com/kijiproject/kiji-mapreduce/commit/7aa0d2718288b83b3d14a4af9247bb4ad72bb6a0