Python 3 version Documentation version needs to match code

[richlysakowski]

Some of Python 3 code still refers to Python v2.6.

This is very confusing and a potential rat hole of lost time trying to use it.

Please update github docs for this.

[alankilborn]

You could expedite the process by pointing out the specific out-of-date areas.

[chcg]

See #155 and #120. Updating the docu is a problem due to the missing activity of the owner of this repo.