Refactor upgrade and verify commands.

app/Console/Commands/Upgrade/UpgradeSkeleton.php.stub

@@ -0,0 +1,84 @@
+<?php
+/**
+ * UpgradeSkeleton.php
+ * Copyright (c) 2019 thegrumpydictator@gmail.com
+ *
+ * This file is part of Firefly III.
+ *
+ * Firefly III 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.
+ *
+ * Firefly III 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 Firefly III. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace FireflyIII\Console\Commands\Upgrade;
+
+use Illuminate\Console\Command;
+
+/**
+ * Class UpgradeSkeleton
+ */
+class UpgradeSkeleton extends Command
+{
+    public const CONFIG_NAME = '4780_some_name';
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'SOME DESCRIPTION';
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $signature = 'firefly-iii:UPGRSKELETON {--F|force : Force the execution of this command.}';
+
+    /**
+     * Execute the console command.
+     *
+     * @return int
+     */
+    public function handle(): int
+    {
+        if ($this->isExecuted() && true !== $this->option('force')) {
+            $this->warn('This command has already been executed.');
+
+            return 0;
+        }
+        $this->warn('Congrats, you found the skeleton command. Boo!');
+
+        //$this->markAsExecuted();
+        return 0;
+    }
+
+    /**
+     * @return bool
+     */
+    private function isExecuted(): bool
+    {
+        $configVar = app('fireflyconfig')->get(self::CONFIG_NAME, false);
+        if (null !== $configVar) {
+            return (bool)$configVar->data;
+        }
+
+        return false; // @codeCoverageIgnore
+    }
+
+
+    /**
+     *
+     */
+    private function markAsExecuted(): void
+    {
+        app('fireflyconfig')->set(self::CONFIG_NAME, true);
+    }
+}