Fix: move friendsofphp/php-cs-fixer to dev dependecies

Author: Imangazaliev

composer.json

@@ -14,11 +14,11 @@
     "require": {
         "php": ">=5.4",
         "ext-dom": "*",
-        "ext-iconv": "*",
-        "friendsofphp/php-cs-fixer": "2.9"
+        "ext-iconv": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8"
+        "phpunit/phpunit": "^4.8",
+        "friendsofphp/php-cs-fixer": "2.9"
     },
     "autoload": {
         "psr-4": {