DanielWagnerHall: Adding units to doc

git-svn-id: http://selenium.googlecode.com/svn/trunk/py@18357 07704840-8298-11de-bf8c-fd130f914ac9
diff --git a/selenium/webdriver/remote/webdriver.py b/selenium/webdriver/remote/webdriver.py
index 0e3302d..675ce7f 100644
--- a/selenium/webdriver/remote/webdriver.py
+++ b/selenium/webdriver/remote/webdriver.py
@@ -636,7 +636,7 @@
            execute_async_script call before throwing an error.
 
         :Args:
-         - time_to_wait: The amount of time to wait
+         - time_to_wait: The amount of time to wait (in seconds)
 
         :Usage:
             driver.set_script_timeout(30)