emberfire/firebase.json

{
  "hosting": {
    "public": "dist",

    "rewrites": [{
      "source": "**",
      "destination": "/index.html"
    }],

    "headers": [{
      "source" : "**/*.@(jpg|jpeg|gif|png|css|js|ico)",
      "headers" : [{
        "key" : "Cache-Control",
        "value" : "public,max-age=604800,s-maxage=604800"
      }]
    }]
  }
}