materialized views: more tests
materialized views: more tests

Additional tests for cases surrounding issue #3362, where base rows
disappear (or not) and view rows need to disappear (or not) as well.
These new tests focus on checking that view_updates::do_delete_old_entry()
is correct.

Signed-off-by: Nadav Har'El <625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>
Message-Id: <20180829131914.16042-2-625169824b719df98706d88646d0aae6f368ae4d@scylladb.com>

scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla