Change demo file back to original output style.

docs/examples/tutorial/fib1/fib.pyx

+from __future__ import print_function
+
 def fib(n):
     """Print the Fibonacci series up to n."""
     a, b = 0, 1
     while b < n:
-        print(b)
+        print(b, end=' ')
         a, b = b, a + b
+
+    print()