Fix docstring codeblock

IPython/testing/__init__.py

@@ -18,7 +18,7 b' def test(**kwargs):'
 
     Any of the options for run_iptestall() may be passed as keyword arguments.
 
-    For example:
+    For example::
     
         IPython.test(testgroups=['lib', 'config', 'utils'], fast=2)