Currently we execute all statements in parallel, but some statements
depend on order, in particular list append/prepend. Fix by executing
sequentially.
Fixes cql_additional_tests.py:TestCQL.batch_and_list_test dtest.
Fixes#1075.
Message-Id: <1458672874-4749-1-git-send-email-tgrabiec@scylladb.com>
(cherry picked from commit 5f44afa311)