beginning implementations of CardCollection and some of its subclasses

BearOnline/cards/collections/_cardcollection.py

@@ -0,0 +1,10 @@
+from collections import deque
+
+from .. import Card
+
+class CardCollection(deque):
+    def __init__(self, iterable, maxlen=None):
+        if not len(iterable) == 0 or all([isinstance(Card, item) for item in iterable]):
+            raise TypeError("CardCollections must only contain Cards")
+        else:
+            super().__init__(iterable, maxlen)