Change default quit key binding to mod+shift+q

features/run_control/modifier.feature

@@ -6,5 +6,5 @@ Feature: `modifier' run control keyword
       modifier :ctrl
       """
     And uhwm is running
-    When I press the ctrl+q keys
+    When I press the ctrl+shift+q keys
     Then uhwm must terminate successfully

features/steps/run_steps.rb

@@ -24,7 +24,7 @@ When /^I run uhwm with options? (-.+)$/ do |options|
 end
 
 When /^I tell uhwm to quit$/ do
-  x_key 'alt+q'
+  x_key 'alt+shift+q'
 end
 
 Then /^the exit status must be (\d+)$/ do |exit_status|