introduce stack build system and restructure code

src/Skat/AI/Stupid.hs

@@ -0,0 +1,18 @@
+module Skat.AI.Stupid where
+
+import Skat.Player
+import Skat.Pile
+import Skat.Card
+
+data Stupid = Stupid { getTeam :: Team
+                     , getHand :: Hand }
+              deriving Show
+
+instance Player Stupid where
+    team = getTeam
+    hand = getHand
+    chooseCard p _ _ hand = do
+        trumpCol <- trumpColour
+        turnCol <- turnColour
+        let possible = filter (isAllowed trumpCol turnCol hand) hand
+        return (head possible, p)