Kanban bucket limits (#652)

Fix integration tests

Generate swagger docs

Add test for moving a task between buckets

Add check for bucket limit when updating a task

Add fixture to ensure a bucket with a high limit will never exceed the limit

Refactor bucket limit check into seperate function

Add test for creating and fix

Fix unexported field

Add error in case a task was added to a bucket which has its limit already exceeded

Add migration to add new task field

Add limit field to buckets

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/652

pkg/migration/20200904101559.go

@@ -0,0 +1,43 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2020 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package migration
+
+import (
+	"src.techknowlogick.com/xormigrate"
+	"xorm.io/xorm"
+)
+
+type buckets20200904101559 struct {
+	Limit int64 `xorm:"default 0" json:"limit"`
+}
+
+func (buckets20200904101559) TableName() string {
+	return "buckets"
+}
+
+func init() {
+	migrations = append(migrations, &xormigrate.Migration{
+		ID:          "20200904101559",
+		Description: "",
+		Migrate: func(tx *xorm.Engine) error {
+			return tx.Sync2(buckets20200904101559{})
+		},
+		Rollback: func(tx *xorm.Engine) error {
+			return nil
+		},
+	})
+}