merged branch jfsimon/fix-tests (PR #8618)

This PR was merged into the master branch.

Discussion
----------

[Console] fix tests

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes

Commits
-------

e4c1b30 [Console] fixed tests

src/Symfony/Component/Console/Descriptor/MarkdownDescriptor.php

@@ -126,9 +126,9 @@ class MarkdownDescriptor extends Descriptor
             }
 
             $this->write("\n\n");
-            $this->write(array_map(function ($commandName) {
+            $this->write(implode("\n", array_map(function ($commandName) {
                 return '* '.$commandName;
-            } , $namespace['commands']));
+            } , $namespace['commands'])));
         }
 
         foreach ($description->getCommands() as $command) {