Upload Error with v2 (migration from v1)

Ok after some investigating I have noticed the first attempt gives no errors, all subsequent attempts give the client modified nonetype error.

After some googling I finally came accross some info that this is a known issue with datetime in python.

I found this:

try:
    datetime.strptime(date_string, format)
except TypeError:
    datetime(*(time.strptime(date_string, format)[0:6]))

So I decided to manually tweak the make stone friendly function in the api to this.

def _make_stone_friendly(
        data_type, val, alias_validators, strict, validate, for_msgpack):
    """
    Convert a Python object to a type that will pass validation by its
    validator.

    Validation by ``alias_validators`` is performed even if ``validate`` is
    false.
    """
    if isinstance(data_type, bv.Timestamp):
        try:
            ret = datetime.datetime.strptime(val, data_type.format)
        except:
            print("datetime.datetime.strptime(val, data_type.format) returned NoneType. Trying alterntive")
            pass
        try:
            ret = datetime.datetime(*(time.strptime(val, data_type.format)[0:6]))
        except (TypeError, ValueError) as e:
            raise bv.ValidationError(e.args[0])
    elif isinstance(data_type, bv.Bytes):
        if for_msgpack:
            if isinstance(val, six.text_type):
                ret = val.encode('utf-8')
            else:
                ret = val
        else:
            try:
                ret = base64.b64decode(val)
            except TypeError:
                raise bv.ValidationError('invalid base64-encoded bytes')
    elif isinstance(data_type, bv.Void):
        if strict and val is not None:
            raise bv.ValidationError("expected null, got value")
        return None
    else:
        if validate:
            data_type.validate(val)
        ret = val
    if alias_validators is not None and data_type in alias_validators:
        alias_validators[data_type](ret)
    return ret

I can say it is now working every time without error.

I'm sure you don't like the code being altered and I can totally understand that but if you think the code doesn't look like it will yeild any issues then I'm happy to do a pull request on github.