Added versioneer and updated setuptools building

[stefdoerr]

No description provided.

[stefdoerr]

Done I think. Tests pass, so we should be fine

[RaulPPelaez]

Looking at the versioneer README it seems like one of the steps requires running "versioneer install --no-vendor".
I understand this is what generated the big _version.py file and it is not required to run it again? (unless to update versioneer I guess).
Also, does this add versioneer as a dependency?

[stefdoerr]

Yes, although I've stopped using that command because it touches too much stuff which I don't want it to. So I usually just copy the _version.py from a previous project, modifying the package name in it and do the rest manually. I don't like sneaky executables modifying my codebase

[RaulPPelaez]

It also appears that versioneer is just a build time dependency, which is nice.

[stefdoerr]

Yes, since we ship that big _version.py file you don't need to add it as a runtime dep