Added toggle to show failed tests on graph

re #285

database/migrations/2020_08_28_192136_add_show_failed_tests_setting.php

@@ -0,0 +1,38 @@
+<?php
+
+use App\Helpers\SettingsHelper;
+use App\Setting;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddShowFailedTestsSetting extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        if(!SettingsHelper::get('show_failed_tests_on_graph')) {
+            Setting::create([
+                'name' => 'show_failed_tests_on_graph',
+                'value' => true,
+                'description' => 'If enabled, failed tests will appear on the graphs as 0.'
+            ]);
+        }
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Setting::whereIn('name', [
+            'show_failed_tests_on_graph',
+        ])->delete();
+    }
+}