Require exact version of php-cs-fixer

Every run of php-cs-fixer must be idempotent, hence even minor updates of this package must be prohibited.

.php_cs

@@ -13,6 +13,12 @@ $config = Symfony\CS\Config\Config::create()
         'no_blank_lines_before_namespace',
         // [contrib] Ordering use statements.
         'ordered_use',
+        // [contrib] Annotations should be ordered so that param annotations come first, then throws annotations, then return annotations.
+        'phpdoc_order',
+        // [contrib] Arrays should use the long syntax.
+        'long_array_syntax',
+        // [contrib] Ensure there is no code on the same line as the PHP open tag.
+        'newline_after_open_tag',
     ))
     ->finder($finder);
 

Dockerfile

@@ -35,7 +35,7 @@ RUN composer global require "mayflower/php-codebrowser"
 RUN composer global require "sebastian/phpcpd"
 RUN composer global require "squizlabs/php_codesniffer"
 RUN composer global require "phploc/phploc"
-RUN composer global require "fabpot/php-cs-fixer"
+RUN composer global require "fabpot/php-cs-fixer=1.8.1"
 
 
 # Documentor dependencies