THINK-217-TRN

Added in a new frontend API. The implementation I think is a bit hacky. But its the only way to get reliable cross-domain support. So basically the campaign root includes a script on the API domain which sets a `token` variable that Adam can use to authenticate to the API. This allows us to track reliably our visitors across domains.
We're as in cruglobal projects? Because the rubocop default is 80?