docs added

tests/acceptance.suite.yml

@@ -15,6 +15,8 @@ modules:
         - PhpBrowser
 # you can use WebDriver instead of PhpBrowser to test javascript and ajax.
 # This will require you to install selenium. See http://codeception.com/docs/04-AcceptanceTests#Selenium
+# "restart" option is used by the WebDriver to start each time per test-file new session and cookies, 
+# it is useful if you want to login in your app in each test.
 #        - WebDriver
     config:
         PhpBrowser:
@@ -22,3 +24,4 @@ modules:
 #        WebDriver:
 #            url: 'http://localhost'
 #            browser: firefox
+#            restart: true