Don't merge in default replication_factor for NetworkTopologyStrategy

It conflicts with other replication values, such as 'datacenter: 1' or 'dc1: 3'
etc.
Merge pull request #24 from gavinheavyside/dont-set-rep-factor-for-network-topology-strategy

Don't merge in defaults for NetworkTopologyStrategy keyspace creation
Support composite partition key as part of composite primary key

e.g. primary_key: [[:id, :version], :field] => PRIMARY KEY ((id, version), field)
Merge pull request #25 from gavinheavyside/composite-partition-key

Support composite partition key as part of composite primary key
Flatten primary keys once in schema.rb.
array and set interpolation for supporting cql3 list and set types
support element deletion from map and list collection types
support collection item updates using CollectionItem class
add require set
delete statement should use placeholders for collections items
cql3 collections usage examples
refactor collections api
add collections example link
Merge pull request #23 from damiancaruso/cql3-collections

CQL3 Collections