cqerl_ts: Add keyspace / table bootstrap support

Change the schema a little, and add keyspace + table bootstrap support,
so it does not need to be created prior to running basho_bench.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
seestar_ts: Drop the driver

The cqerl driver can do the same things, and more, while being more
performant. Drop this driver, as it is not needed anymore.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>