fix notification chanels and more tests (#108)

* fix notification chanels and more tests

* fix code style

tests/Unit/SSHCommands/Storage/DownloadFromDropboxCommandTest.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Tests\Unit\SSHCommands\Storage;
+
+use App\SSHCommands\Storage\DownloadFromDropboxCommand;
+use Tests\TestCase;
+
+class DownloadFromDropboxCommandTest extends TestCase
+{
+    public function test_generate_command()
+    {
+        $command = new DownloadFromDropboxCommand('src', 'dest', 'token');
+
+        $expected = <<<EOD
+        curl -o dest --location --request POST 'https://content.dropboxapi.com/2/files/download' \
+        --header 'Accept: application/json' \
+        --header 'Dropbox-API-Arg: {"path":"src"}' \
+        --header 'Authorization: Bearer token'
+        EOD;
+
+        $this->assertStringContainsString($expected, $command->content());
+    }
+}