Empty list becomes a tuple in AttrDict

[deti]

In Python 3.5 with attrdict 2.0.0

first_dict = AttrDict()
first_dict.second_list = list()
for i in range(10):
    first_dict.second_list.append(i)
print("Debug dict. Attr dict01: '{}'".format(first_dict))

Gives

AttributeError: 'tuple' object has no attribute 'append'

It looks like AttrDict converts empty lists into tuples.

[jonschull]

Not just 3.5

#34