Add AbstractChainedBatch extendability tests
Add AbstractChainedBatch extendability tests

bigeasy/abstract-leveldown,Level/abstract-leveldown,bryce-gibson/SQLdown,shimonenator/couchbasedown,bryce-gibson/SQLdown,calvinmetcalf/SQLdown,calvinmetcalf/SQLdown,snowyu/node-abstract-nosql,ralphtheninja/abstract-leveldown,ralphtheninja/abstract-leveldown,watson/abstract-leveldown