test: fix race in namesys tests

Resolves #4018

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>

namesys/namesys_test.go

@@ -12,6 +12,7 @@ import (
 
 	ci "gx/ipfs/QmP1DfoUjiWH2ZBo1PBH6FupdBucbDepx3HpWmEY6JMUpY/go-libp2p-crypto"
 	ds "gx/ipfs/QmVSase1JP7cq9QkPT46oNwdp9pT6kBkG3oqS14y3QcZjG/go-datastore"
+	dssync "gx/ipfs/QmVSase1JP7cq9QkPT46oNwdp9pT6kBkG3oqS14y3QcZjG/go-datastore/sync"
 )
 
 type mockResolver struct {
@@ -76,7 +77,7 @@ func TestNamesysResolution(t *testing.T) {
 }
 
 func TestPublishWithCache0(t *testing.T) {
-	dst := ds.NewMapDatastore()
+	dst := dssync.MutexWrap(ds.NewMapDatastore())
 	priv, _, err := ci.GenerateKeyPair(ci.RSA, 1024)
 	if err != nil {
 		t.Fatal(err)