Creative Commons Attribution no version

[Silviu-Caprar]

Hello,

What version of Creative Commons Attribution applies on the files:
https://github.com/PythonCharmers/python-future/blob/v0.17.0/docs/compatible_idioms.rst
and
https://github.com/PythonCharmers/python-future/blob/v0.17.0/docs/notebooks/Writing%20Python%202-3%20compatible%20code.ipynb ?

Please specify this for python-future 0.17.0 and also it will be easier to know for new versions of python-future about the exact version of Creative Commons Attribution found inside these files.

Thanks.