graph/db: rename V1Store to Store

The underling store will store gossip messages across gossip versions
and we will instead expose version parameters on many of the methods. So
this interface really just abstracts the underlying store/schema type.

graph/db/test_sqlite.go

@@ -13,7 +13,7 @@ import (
 
 // NewTestDB is a helper function that creates a SQLStore backed by a SQL
 // database for testing.
-func NewTestDB(t testing.TB) V1Store {
+func NewTestDB(t testing.TB) Store {
 	return NewTestDBWithFixture(t, nil)
 }
 
@@ -24,7 +24,7 @@ func NewTestDBFixture(_ *testing.T) *sqldb.TestPgFixture {
 
 // NewTestDBWithFixture is a helper function that creates a SQLStore backed by a
 // SQL database for testing.
-func NewTestDBWithFixture(t testing.TB, _ *sqldb.TestPgFixture) V1Store {
+func NewTestDBWithFixture(t testing.TB, _ *sqldb.TestPgFixture) Store {
 	store, err := NewSQLStore(
 		&SQLStoreConfig{
 			ChainHash: *chaincfg.MainNetParams.GenesisHash,