BC break for python 2.7 and 3.5 on existing tags

[wesobi]

The dependency on Jinja gets the latest version above 2.7.2. in their 3.0.0 version, they dropped python 2.7 and 3.5 support.

The jinja dependency should have a max version set, so version that were working with python 2.7 and 3.5 in the past should not fail all of a sudden.

Future version, imo, should simply not support python 2.7 and 3.5 anymore, but at least this will not break current versions for users (eventhough staying on these versions of python is not encouraged).

I've created a fix for now at #52 , but this will ofc not retroactively update all the versions which are broken up until now. At least it will give a version that is not broken up until now for these users, unless it is an active decision to discourage use of python 2.7/3.5