build+multi: switch from bolt to bbolt

In this commit, we switch from boltbd/bolt to coreos/bbolt as the
former is no longer being actively maintained.

macaroons/service.go

@@ -14,7 +14,7 @@ import (
 
 	"golang.org/x/net/context"
 
-	"github.com/boltdb/bolt"
+	"github.com/coreos/bbolt"
 )
 
 var (

macaroons/store.go

@@ -7,7 +7,7 @@ import (
 
 	"golang.org/x/net/context"
 
-	"github.com/boltdb/bolt"
+	"github.com/coreos/bbolt"
 
 	"github.com/roasbeef/btcwallet/snacl"
 )

macaroons/store_test.go

@@ -7,7 +7,7 @@ import (
 	"path"
 	"testing"
 
-	"github.com/boltdb/bolt"
+	"github.com/coreos/bbolt"
 
 	"github.com/lightningnetwork/lnd/macaroons"