fix CI

closes GH-81

Author: mmoll

.github/workflows/ci.yml

@@ -17,11 +17,7 @@ jobs:
         # Nix Flakes doesn't work on shallow clones
         fetch-depth: 0
 
-    - uses: cachix/install-nix-action@v12
-      with:
-        install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20201221_9fab14a/install
-        extra_nix_config: |
-          experimental-features = nix-command flakes
+    - uses: cachix/install-nix-action@v18
 
     - name: Cache Composer dependencies
       uses: actions/cache@v2

src/PHPCodeBrowser/IssueXML.php

@@ -106,7 +106,7 @@ public function __construct(string $version = '1.0', string $encoding = 'UTF-8')
             $this->createElement('codebrowser')
         );
         $this->preserveWhiteSpace = false;
-        $this->formatOutput = true;
+        $this->formatOutput       = true;
     }
 
     /**