TT#70901 selenium: take screenshot if preperation fails

preperation will now take a screenshot if it fails

Change-Id: I3e5695ccd6a41c670daba47f1e6d3406327c5595

t/selenium/testrun.py

@@ -36,6 +36,7 @@ filename = 0
 def preparation():
     global customers
     driver = create_driver()
+    try:
         login_panel(driver)
         for i in range(0, int(os.environ['THREADS'])):
             customers[create_customer(driver)] = create_domain(driver)
@@ -43,6 +44,8 @@ def preparation():
         for customer in customers.keys():
             create_subscriber(driver, customer, customers[customer])
         driver.quit()
+    except Exception:
+        driver.save_screenshot('/results/preperation.png')
 
 
 def cleanup():