update vendor/ dir to latest w/o heroku, moby

had to lock a lot of things in place

vendor/github.com/go-sql-driver/mysql/utils_go18.go

@@ -12,6 +12,7 @@ package mysql
 
 import (
 	"crypto/tls"
+	"database/sql"
 	"database/sql/driver"
 	"errors"
 )
@@ -31,3 +32,18 @@ func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
 	}
 	return dargs, nil
 }
+
+func mapIsolationLevel(level driver.IsolationLevel) (string, error) {
+	switch sql.IsolationLevel(level) {
+	case sql.LevelRepeatableRead:
+		return "REPEATABLE READ", nil
+	case sql.LevelReadCommitted:
+		return "READ COMMITTED", nil
+	case sql.LevelReadUncommitted:
+		return "READ UNCOMMITTED", nil
+	case sql.LevelSerializable:
+		return "SERIALIZABLE", nil
+	default:
+		return "", errors.New("mysql: unsupported isolation level: " + string(level))
+	}
+}