Implement Aerospike Datastore

Aerospike is a NoSQL database solution for real-time operational applications, delivering predictable performance at scale, superior uptime, and high availability at the lowest TCO compared to first-generation NoSQL and relational databases. It could be nice to support Aerospike as a datastore at Gora. Aerospike uses Apache v2 license for Java client and uses aGPL license for Aerospike Server Community Edition. (http://www.aerospike.com/products/)