Adhere to semver

We use typically "1.0.0-1", where the "-1" signifies build id.

However according to semver, this signifies prerelease id, and a "+" prefix signifies build id, as such:

>>> ver = semver.Version.parse('1.2.3-pre.2+build.4')
>>> ver.major
1
>>> ver.minor
2
>>> ver.patch
3
>>> ver.prerelease
'pre.2'
>>> ver.build
'build.4'


https://pypi.org/project/semver/