Disable pydebug for CPython that runs tests.
Disable pydebug for CPython that runs tests.

pip installs release-mode packages even for debug-mode CPython, which
results in:

    python2.7: Objects/object.c:65: _Py_AddToAllObjects: Assertion
                 `(op->_ob_prev == NULL) == (op->_ob_next == NULL)' failed.

So defaulting back to release-mode CPython.

arskom/spyne,arskom/spyne,arskom/spyne