This suite fails on Python 3 (with and without -builtin) due to the following issues:
- Operator / is mapped to the div slot which is now truediv in Python3 (see PR #136 for a WIP fix).
- Operators +=, -=, *= and probably others assign the method return type (void) to the object they are applied on. A workaround is to return *this from the affected operators.
