Add notifications package for easy sending of notifications (#779)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/779
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

pkg/migration/20210207192805.go

@@ -0,0 +1,48 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2021 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 Affero General Public Licensee 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 Affero General Public Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package migration
+
+import (
+	"time"
+
+	"src.techknowlogick.com/xormigrate"
+	"xorm.io/xorm"
+)
+
+type notifications20210207192805 struct {
+	ID           int64       `xorm:"bigint autoincr not null unique pk" json:"id"`
+	NotifiableID int64       `xorm:"bigint not null" json:"-"`
+	Notification interface{} `xorm:"json not null" json:"notification"`
+	Created      time.Time   `xorm:"created not null" json:"created"`
+}
+
+func (notifications20210207192805) TableName() string {
+	return "notifications"
+}
+
+func init() {
+	migrations = append(migrations, &xormigrate.Migration{
+		ID:          "20210207192805",
+		Description: "Add notifications table",
+		Migrate: func(tx *xorm.Engine) error {
+			return tx.Sync2(notifications20210207192805{})
+		},
+		Rollback: func(tx *xorm.Engine) error {
+			return nil
+		},
+	})
+}