chore: Show the diff for the makefile (#31)

Author: theofidry

Makefile

@@ -21,7 +21,7 @@ PHPUNIT_COVERAGE_HTML = XDEBUG_MODE=coverage $(PHPUNIT) --coverage-html=$(COVERA
 PHPUNIT_COVERAGE = XDEBUG_MODE=coverage $(PHPUNIT) --coverage-xml=$(COVERAGE_DIR)/coverage-xml --log-junit=$(COVERAGE_DIR)/phpunit.junit.xml
 
 PHP_CS_FIXER_BIN = vendor-bin/php-cs-fixer/vendor/friendsofphp/php-cs-fixer/php-cs-fixer
-PHP_CS_FIXER = $(PHP_CS_FIXER_BIN) fix --ansi --verbose --config=.php-cs-fixer.php
+PHP_CS_FIXER = $(PHP_CS_FIXER_BIN) fix --ansi --verbose --config=.php-cs-fixer.php --diff
 
 RECTOR_BIN = vendor-bin/rector/vendor/bin/rector
 RECTOR = $(RECTOR_BIN)