Added all required dependencies

vendor/github.com/go-xorm/builder/builder_update.go

@@ -0,0 +1,37 @@
+package builder
+
+import (
+	"errors"
+	"fmt"
+)
+
+func (b *Builder) updateWriteTo(w Writer) error {
+	if len(b.tableName) <= 0 {
+		return errors.New("no table indicated")
+	}
+	if len(b.updates) <= 0 {
+		return errors.New("no column to be update")
+	}
+
+	if _, err := fmt.Fprintf(w, "UPDATE %s SET ", b.tableName); err != nil {
+		return err
+	}
+
+	for i, s := range b.updates {
+		if err := s.opWriteTo(",", w); err != nil {
+			return err
+		}
+
+		if i != len(b.updates)-1 {
+			if _, err := fmt.Fprint(w, ","); err != nil {
+				return err
+			}
+		}
+	}
+
+	if _, err := fmt.Fprint(w, " WHERE "); err != nil {
+		return err
+	}
+
+	return b.cond.WriteTo(w)
+}