Add coding exercises for Facebook interviews

Add attempts at solving coding problems to Briefcase.

scratch/facebook/delete-node.py

@@ -0,0 +1,19 @@
+from linked_list import Node, from_list
+
+def delete(node):
+    if not node.next:
+        node.value = None
+    else:
+        node.value = node.next.value
+        node.next = node.next.next
+
+one = Node(1)
+two = Node(2)
+three = Node(3)
+
+one.next = two
+two.next = three
+
+print(one)
+delete(two)
+print(one)