ApiOptions.__and__ generates exception in Python3

[baecks]

Hello,

In the file options.py, the inplementation of the method and in the class ApiOptions generates an exception in Python3. The reason for this exception is that dict_items can not be added in Py3. The alternative implementation for this method, which is Python 2 and 3 compliant (tested locally) is provided below:

class ApiOptions(dict):
    def __and__(self, other):
        d = self.copy()
        d.update(other)
        return ApiOptions(d)

Could you please apply this fix to the official code repo?

Thanks,
Sven.