Allow options to specify setting replication strategy and settings from cequel.yml config file.

http://www.datastax.com/documentation/cql/3.0/cql/cql_reference/create_keyspace_r.html

Based on the config file settings used in create_keyspace https://github.com/reachlocal/cequel-migrations-rails/blob/master/lib/cequel-migrations-rails/keyspace_manager.rb#L16.