Merge pull request #31 from sajinidesilva/slot_Imp

added new attributes to andes-config.xml
Use cassandra-driver-core instead of cql-driver
Merge pull request #32 from a5anka/cassandra_driver_change

Use cassandra-driver-core instead of cql-driver
Merge pull request #33 from sajinidesilva/slot_Imp

changed andes-config.xml
changed error logs