Before this commit our build had this option:
-ldflags "-X github.com/mickael-kerjean/filestash/server/common.BUILD_DATE=`date -u +%Y%m%d` -X github.com/mickael-kerjean/filestash/server/common.BUILD_REF=`git rev-parse HEAD`"
Doing this via a generator is much easier for people getting started
with Filestash
