Add tasks for all the new languages

Task/Fibonacci-sequence/Wart/fibonacci-sequence-1.wart

@@ -0,0 +1,4 @@
+def (fib n)
+  if (n < 2)
+    n
+    (+ (fib n-1) (fib n-2))

Task/Fibonacci-sequence/Wart/fibonacci-sequence-2.wart

@@ -0,0 +1,5 @@
+def (fib n)
+  (+ (fib n-1) (fib n-2))
+
+def (fib n) :case (n < 2)
+  n

Task/Fibonacci-sequence/Wart/fibonacci-sequence-3.wart

@@ -0,0 +1,6 @@
+def (fib n saved)
+  # all args in wart are optional, and we expect callers to not provide saved
+  default saved :to (table 0 0 1 1)  # pre-populate base cases
+  default saved.n :to
+    (+ (fib n-1 saved) (fib n-2 saved))
+  saved.n