Remove support for Python 3.4

[FlorianWilhelm]

Describe your use-case

Python 3.4 reaches end of lifetime march 2019. After that the support for it can be safely removed.

[FlorianWilhelm]

Done in 7a8dc16

[abravalheri]

Hi @FlorianWilhelm, do you think the best is to fast-forward to 3.6, instead of 3.5?
Ubuntu (which is very popular) and other distros I suspect, still support 3.5
(see 16.06 LTS and its python3 package).

Moreover we can see that official support for 3.5 is still going on here.

[FlorianWilhelm]

Hm... good point, the end of life for Python 3.5 is 2020-09-13 and so far major versions like PyScaffold needed more than one year as I have little time, that's why I thought it will surely take some time for PyScaffold 4.0 and thus Python 3.6 will be fine. What would be your time estimation with the current feature set we have?

[abravalheri]

It's hard to estimate...
If we just have to rewrite how name and project-path work, allow in-place updates, and change the namespace to create empty __init__.py , it might be OK, but one never know (specially because we need to make the extensions compatible as well).

Can we do something like officially supporting 3.6 (included in the docs), but not enforce it in setup_requires? This way even if we release PyScaffold 4.0 closer to the end of life of Python 3.5, we don't have to release a following major version just to drop the support and be consistent with semantic versioning.

[FlorianWilhelm]

@abravalheri, good points. That's fine for me, so you can just switch back to Python 3.5 in setup.cfg and the template for it as well I guess.