Update python versions, include changes from kxxoling

[pcraciunoiu]

I can't speak for all these changes, but I'd love it if the parent of all our forks was the most up to date version.

[scorphus]

Hi, thanks for proposing the improvements. I'll accept them partially. Things like the new .editorconfig file and the addition of more recent Python versions are nice to have. Other changes do not relate to the project, such as removing the copyright notice from all the files – this could be a y/n option thou.

[scorphus]

Before I accept them, however, would you please fix the errors on Travis?