add in MRE for devs to look at

tests/run/libcpp_all.pyx

@@ -116,3 +116,12 @@ assert vec_alloc_int.size() == 10
 
 cdef libcpp.list.list[int,allocator[int]] list_alloc_int = libcpp.list.list[int,allocator[int]](10,1)
 assert list_alloc_int.size() == 10
+
+##Something about the default params breaks the auto-conversion...
+def convert_to_vector(I):
+    """
+    >>> convert_to_vector([1,2,3,4])
+    """
+    cdef vector[int] x = I
+
+