Merge pull request #6720 from paritytech/kvdb_split

separated kvdb into 3 crates: kvdb, kvdb-memorydb && kvdb-rocksdb

sync/src/tests/helpers.rs

@@ -291,7 +291,7 @@ impl TestNet<EthPeer<EthcoreClient>> {
 		let client = EthcoreClient::new(
 			ClientConfig::default(),
 			&spec,
-			Arc::new(::kvdb::in_memory(::ethcore::db::NUM_COLUMNS.unwrap_or(0))),
+			Arc::new(::kvdb_memorydb::create(::ethcore::db::NUM_COLUMNS.unwrap_or(0))),
 			Arc::new(Miner::with_spec_and_accounts(&spec, accounts)),
 			IoChannel::disconnected(),
 		).unwrap();