Add leveldb to db backend and fix error wrapping

go.mod

@@ -16,11 +16,14 @@ require (
 	github.com/go-redis/redis/v8 v8.3.0
 	github.com/gomodule/redigo v1.8.2 // indirect
 	github.com/imdario/mergo v0.3.9
+	github.com/pkg/errors v0.9.1
 	github.com/pkg/profile v1.4.0
 	github.com/ryszard/goskiplist v0.0.0-20150312221310-2dfbae5fcf46
 	github.com/smartystreets/goconvey v1.6.4
+	github.com/syndtr/goleveldb v1.0.0
 	github.com/urfave/cli v1.22.3
 	github.com/yuin/gopher-lua v0.0.0-20191220021717-ab39c6098bdb // indirect
 	golang.org/x/sys v0.0.0-20200519105757-fe76b779f299
+	google.golang.org/protobuf v1.23.0
 	gopkg.in/op/go-logging.v1 v1.0.0-20160211212156-b2cb9fa56473
 )