Convert Qt main window setup into Kivy app.

justcheckers/app.py

@@ -19,6 +19,9 @@ LOG = logging.getLogger(__name__)
 
 
 class JustCheckersApp(App):
+    title = 'justCheckers'
+    icon = 'images/icon.png'
+
     def on_start(self):
         log_system_and_game_info()
         super(JustCheckersApp, self).on_start()

justcheckers/justcheckers.kv

@@ -1,5 +1,8 @@
 #: import justcheckers justcheckers
 
-BoxLayout:
+FloatLayout:
+    Image:
+        source: 'images/backdrop.jpg'
+    BoxLayout:
         Label:
             text: "justCheckers {}".format(justcheckers.__version__)