Rename migrations package, to match goose generated migration files

db/migration/20200325185135_add_album_artist_id.go

@@ -1,34 +0,0 @@
-package migration
-
-import (
-	"database/sql"
-
-	"github.com/pressly/goose"
-)
-
-func init() {
-	goose.AddMigration(Up20200325185135, Down20200325185135)
-}
-
-func Up20200325185135(tx *sql.Tx) error {
-	_, err := tx.Exec(`
-alter table album
-	add album_artist_id varchar(255) default '';
-create index album_artist_album_id
-	on album (album_artist_id);
-
-alter table media_file
-	add album_artist_id varchar(255) default '';
-create index media_file_artist_album_id
-	on media_file (album_artist_id);
-`)
-	if err != nil {
-		return err
-	}
-	notice(tx, "A full rescan will be performed!")
-	return forceFullRescan(tx)
-}
-
-func Down20200325185135(tx *sql.Tx) error {
-	return nil
-}