def __add__(self, other):
return self.copy().__iadd__(other)<EOL>
Add two Tribes or a Tribe and a Template together. '+'

.. rubric:: Example

>>> tribe = Tribe(templates=[Template(name='a')])
>>> tribe_ab = tribe + Tribe(templates=[Template(name='b')])
>>> print(tribe_ab)
Tribe of 2 templates
>>> tribe_abc = tribe_ab + Template(name='c')
>>> print(tribe_abc)
Tribe of 3 templates