py: fix syntax errors

python_payload/apps/demo_mandelbrot.py

-from application import Application
+from st3m.application import Application
 import ui
 
 class MandelbrotApp(Application):
@@ -25,7 +25,7 @@ class MandelbrotApp(Application):
         
         for x in range(-240,240):
             for y in range(-240,240):
-                
+                pass
 
 app=MandelbrotApp("Mandelbrot")
 app.run()
\ No newline at end of file

python_payload/apps/flow3roids.py

-from application import SimpleApplication
+from st3m.application import SimpleApplication
 
 app = SimpleApplication("flow3rdroids")
 
@@ -17,6 +17,8 @@ def on_draw():
 
 def on_scroll_step(direction):
     #TODO: ship_direction += direction * angle
+    pass
 
-def def on_enter():
+def on_enter():
     #TODO:ship_direction += speed
+    pass