Prepare semver 3.0.0

Situation

As we have released 2.9.0 of semver, we should consider of moving to 3.0.0 soon. This is needed to start working on adding new features and optimizing source code for Python 3.

(I’ve created this issue to make the upcoming 3.0.0 more visible and to have a record when we need to search the history.)

Suggested Solution

In order to create semver 3.0.0, we need to think about the following tasks:

• Create a maintenance branch for 2.x.y line: maint/v2
• Remove test target py27 and py34 from tox.ini
• Tag the 2.9.0 release.
• Update the Trove classifiers in setup.py and remove support for Python 2.7 and 3.4.
• Optimize source code for Python 3 only and remove any code that was introduced due to 2.7.
• Provide (and label it correctly) the 2.9.0 documentation for ReadTheDocs. We need a configuration that should be possible that old (2.9.x) and new versions (3.*) are still available and can coexit together peacefully. 😉
• Change version number in master to 3.0.0.

Anything else? 😉

I’ve updated the description in https://github.com/k-bx/python-semver/issues/161#issuecomment-539045512 of issue #161

[tlaferriere]

I have just read that python 3.5 has reached end of life. I think we should go ahead and focus on supporting python >= 3.6 since there are quite a few features relating to type hints that could be useful to us that were only added in 3.6.

[tomschr]

Good catch! Thanks for the hint! I’ve updated setup.py and tox.ini accordingly.