Support Aerospike as meta engine

[melin]

Aerospike数据存储在磁盘，索引在内存，相比redis 有4-5倍的性能，支持分布式集群。支持二级索引，丰富的数据结构，秒杀redis https://github.com/aerospike/aerospike-server

[solracsf]

Seems a good option, and a Go client is available: https://github.com/aerospike/aerospike-client-go/tree/v6

[SandyXSD]

We don't have enough energy for this. A PR is welcome, though.