Added wheels to slot machine.

src/py/slots/Slots.py

@@ -1,6 +1,9 @@
 from Wheel import Wheel
 
 class SlotMachine():
-    def __init__(self):
+    def __init__(self, screen_w=3, screen_h=3):
         jackpot = 0
-        wheel = Wheel()
+        wheels=[]
+        for i in range(screen_w):
+            wheel = Wheel(size=screen_h)
+            wheels.append(wheel)