Refuse merge until all required status checks success (#7481)

* refuse merge until ci successfully

* deny merge request when required status checkes not succeed on merge Post and API

* add database migration for added columns on protected_branch

* fix migration

* fix protected branch check bug

* fix protected branch settings

* remove duplicated code on check pull request's required commit statuses pass

* remove unused codes

* fix migration

* add newline for template file

* fix go mod

* rename function name and some other fixes

* fix template

* fix bug pull view

* remove go1.12 wrong dependencies

* add administrator bypass when protected branch status check enabled

* fix bug

* improve the codes

models/migrations/v94.go

@@ -0,0 +1,24 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import "github.com/go-xorm/xorm"
+
+func addStatusCheckColumnsForProtectedBranches(x *xorm.Engine) error {
+	type ProtectedBranch struct {
+		EnableStatusCheck   bool     `xorm:"NOT NULL DEFAULT false"`
+		StatusCheckContexts []string `xorm:"JSON TEXT"`
+	}
+
+	if err := x.Sync2(new(ProtectedBranch)); err != nil {
+		return err
+	}
+
+	_, err := x.Cols("enable_status_check", "status_check_contexts").Update(&ProtectedBranch{
+		EnableStatusCheck:   false,
+		StatusCheckContexts: []string{},
+	})
+	return err
+}