[TEST] erp5: use bstr+ustr as builtin string types

As of pygolang-0.1-121-gcb0e6055 runwsgi starts and serves "welcome" page ok, but I did not check further.

/cc @kazuhiko, @jerome
Status Job ID Name Coverage
  External
running ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

06:45:49

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

00:22:05

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

00:22:19

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

27:50:20

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

08:46:42

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

35:50:17

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

30:18:58

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

32:20:32

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

35:53:49

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

16:17:43

failed ERP5.UnitTest-Zope4Py3-pygolang-bstr-py2

31:24:26