Refactor cucumber steps (quitting uhwm)

lib/uh/wm/testing/acceptance_helpers.rb

@@ -5,6 +5,7 @@ module Uh
     module Testing
       module AcceptanceHelpers
         TIMEOUT_DEFAULT = 2
+        QUIT_KEYBINDING = 'alt+shift+q'.freeze
 
         def uhwm_run options = '-v'
           command = %w[uhwm]
@@ -12,6 +13,10 @@ module Uh
           @interactive = @process = run command.join ' '
         end
 
+        def uhwm_request_quit
+          x_key QUIT_KEYBINDING
+        end
+
         def uhwm_ensure_stop
           if @process
             x_key 'alt+shift+q'