Init: bootstrap go module with basic framework

cmd/migrates/rollback.go

@@ -0,0 +1,33 @@
+package migrates
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var rollbackCmd = &cobra.Command{
+	Use:   "rollback",
+	Short: "Rollback from last migration group",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		ctx := cmd.Context()
+
+		if err := migrator.Lock(ctx); err != nil {
+			return err
+		}
+		defer migrator.Unlock(ctx)
+
+		group, err := migrator.Rollback(ctx)
+		if err != nil {
+			return err
+		}
+
+		if group.IsZero() {
+			fmt.Printf("there are no groups to roll back\n")
+			return nil
+		}
+
+		fmt.Printf("roll back from %s\n", group)
+		return nil
+	},
+}