incompatible code between HEAD of master and tag v1.2.0

[yhaoyan]

Dear developer,

I see that some code IS NOT incompatible in generator.go

The code from tab v1.2.0
https://github.com/satori/go.uuid/blob/f58768cc1a7a7e77a3bd49e98cdd21419399b6a3/generator.go

BUT the code from HEAD of master is
https://github.com/satori/go.uuid/blob/master/generator.go

When I using go get I wiil get the lastest code which tags v1.2.0 but not the really code from HEAD of master.

May I make a PR with a new tag v1.2.1 or any way to resovle it?

[cameracker]

@yhaoyan #103