Handle git tags inside release-gem
Handle git tags inside release-gem

Bundler's `rake release` tries `git push && git push --tags`, but the former
can't work during a Shipit deploy because we're not on a specific branch.

So we're doing the tagging ourself.

Shopify/shipit-engine,Shopify/shipit-engine,Shopify/shipit-engine,Shopify/shipit-engine,Shopify/shipit-engine