Rename migrations package, to match goose generated migration files

db/migration/20200310171621_enable_search_by_albumartist.go

@@ -1,20 +0,0 @@
-package migration
-
-import (
-	"database/sql"
-
-	"github.com/pressly/goose"
-)
-
-func init() {
-	goose.AddMigration(Up20200310171621, Down20200310171621)
-}
-
-func Up20200310171621(tx *sql.Tx) error {
-	notice(tx, "A full rescan will be performed to enable search by Album Artist!")
-	return forceFullRescan(tx)
-}
-
-func Down20200310171621(tx *sql.Tx) error {
-	return nil
-}