Change the release versions to use a git tag

[nwneisen]

Expected Behavior

When creating a release, it would be nice to tag the latest commit on master with the release version and then have the code base automatically use this tag for the generated files.

Care should be taken to make sure that an alternative version is used when doing a dev build. This way it at least takes effort to create versions of a release.

Actual Behavior

The current process involves creating a PR to bump the version in

• VERSION
• version.go
• common.mk

The extra PR is unnecessary paperwork. These can be modified to just pull the latest tag that matches semantic versioning

[nwneisen]

This was done as part of #284