Cypclass test distutil & doctest: inheritance

nogil_test/cypclass_test_inheritance.pyx

+# mode: run
+# distutils: language=c++
+# distutils: extra_compile_args=-std=c++11
+# tag: cpp
+
 cdef cypclass SomeMemory:
   int a
   void __init__(self, int a):
@@ -26,4 +31,10 @@ cpdef baz():
   return o3.getter()
 
 def bag():
+  """
+  >>> bag()
+  14
+  9
+  2
+  """
   return str(foo()) + '\n' + str(bar()) + '\n' + str(baz())