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

templates/repo/pulls/status.tmpl

@@ -15,7 +15,12 @@
         <div class="ui attached segment">
             <span>{{template "repo/commit_status" .}}</span>
             <span class="ui">{{.Context}} <span class="text grey">{{.Description}}</span></span>
-            <div class="ui right">{{if .TargetURL}}<a href="{{.TargetURL}}">Details</a>{{end}}</div>
+            <div class="ui right">
+                {{if $.is_context_required}}
+                    {{if (call $.is_context_required .Context)}}<div class="ui label">Required</div>{{end}} 
+                {{end}}
+                <span class="ui">{{if .TargetURL}}<a href="{{.TargetURL}}">Details</a>{{end}}</span>
+            </div>
         </div>
     {{end}}
-{{end}}
+{{end}}