Expanded query and batch API to support retrieving the consistency level.
Added missing expansion of RetryableQuery API.
Merge pull request #260 from phillipCouto/expand_query_api

Expanded query and batch API to support retrieving the consistency level
Added topology_test.go to test RoundRobin structure at 100% coverage.
Merge pull request #262 from phillipCouto/add_topology_tests

Added topology_test.go to test RoundRobin structure at 100% coverage.