Swiftlint File Header

.swiftlint.yml

@@ -1,5 +1,26 @@
 opt_in_rules:
   - force_unwrapping
+  - file_header
 
 excluded:
   - .build
+
+file_header:
+    severity: error
+    required_pattern: |
+                      \/\/  .*?\.swift
+                      \/\/  .*?
+                      \/\/
+                      \/\/  This file is part of Whisky\.
+                      \/\/
+                      \/\/  Whisky 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\.
+                      \/\/
+                      \/\/  Whisky 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 Whisky\.
+                      \/\/  If not, see https:\/\/www\.gnu\.org\/licenses\/\.
+                      \/\/