feat(cad): change destination of CAD in email to FxA-controlled page (#2297) r=@philbooth
feat(cad): change destination of CAD in email to FxA-controlled page (#2297) r=@philbooth

Fixes #1860
mozilla/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,eoger/fxa-auth-server,mozilla/fxa-auth-server,mozilla/fxa-auth-server,mozilla/fxa-auth-server,eoger/fxa-auth-server