NewVersion returns a Version instance with values set based on the `-ldflags` and some sensible defaults.

BranchString is set by -ldflags in the Makefile - it contains the branch at the time the project was built.

RevString is set by -ldflags in the Makefile - it contains the full git revision at the time the project was built.

VersionString is set by -ldflags in the Makefile - it contains the latest version (tag or short rev) at the time the project was built.

The Version struct contains data that is set when building via `-ldflags` in the Makefile.