Fix fib example

Author: Eloitor

Diff for: example/fib.bl

@@ -1,7 +1,9 @@
 # Computes fib(10) recursively.
 
-def fib (n? : Int) =
+def fib n? : Int =
     if n < 2 then 
         n 
     else 
         (fib n - 1) + (fib n - 2)
+
+println fib 10