update go-merkledag too v0.2.4

Author: frrist

car.go

@@ -47,7 +47,7 @@ func WriteCar(ctx context.Context, ds format.DAGService, roots []cid.Cid, w io.W
 
 	seen := cid.NewSet()
 	for _, r := range roots {
-		if err := dag.EnumerateChildren(ctx, cw.enumGetLinks, r, seen.Visit); err != nil {
+		if err := dag.Walk(ctx, cw.enumGetLinks, r, seen.Visit); err != nil {
 			return err
 		}
 	}

go.mod

@@ -1,12 +1,26 @@
 module github.com/ipfs/go-car
 
 require (
+	github.com/fd/go-nat v1.0.0 // indirect
+	github.com/gxed/pubsub v0.0.0-20180201040156-26ebdf44f824 // indirect
 	github.com/ipfs/go-block-format v0.0.2
-	github.com/ipfs/go-cid v0.0.1
+	github.com/ipfs/go-cid v0.0.2
 	github.com/ipfs/go-ipfs-blockstore v0.0.1
-	github.com/ipfs/go-ipld-cbor v0.0.1
-	github.com/ipfs/go-ipld-format v0.0.1
-	github.com/ipfs/go-merkledag v0.0.1
-	github.com/multiformats/go-multihash v0.0.1
+	github.com/ipfs/go-ipfs-flags v0.0.1 // indirect
+	github.com/ipfs/go-ipld-cbor v0.0.2
+	github.com/ipfs/go-ipld-format v0.0.2
+	github.com/ipfs/go-merkledag v0.2.4
+	github.com/libp2p/go-conn-security v0.0.1 // indirect
+	github.com/libp2p/go-libp2p-host v0.0.1 // indirect
+	github.com/libp2p/go-libp2p-interface-pnet v0.0.1 // indirect
+	github.com/libp2p/go-libp2p-metrics v0.0.1 // indirect
+	github.com/libp2p/go-libp2p-routing v0.0.1 // indirect
+	github.com/libp2p/go-libp2p-transport v0.0.4 // indirect
+	github.com/multiformats/go-multihash v0.0.5
 	github.com/urfave/cli v1.20.0
+	github.com/whyrusleeping/go-smux-multiplex v3.0.16+incompatible // indirect
+	github.com/whyrusleeping/go-smux-multistream v2.0.2+incompatible // indirect
+	github.com/whyrusleeping/go-smux-yamux v2.0.8+incompatible // indirect
+	github.com/whyrusleeping/yamux v1.1.5 // indirect
+	google.golang.org/genproto v0.0.0-20180831171423-11092d34479b // indirect
 )