{
   "browsers": [
      [
         {
            "type": "chrome-in-docker"
         },
         {
            "type": "firefox-in-docker"
         }
      ],
      [
         {
            "type": "phantomjs"
         },
         {
            "type": "opera-in-docker"
         }
      ]
   ]
}

{
   "browsers": [
      [
         {
            "type": "chrome-in-docker"
         },
         {
            "type": "firefox-in-docker"
         }
      ],
      [
         {
            "type": "chrome"
         },
         {
            "type": "phantomjs"
         }
      ]
   ]
}

Simplify JSON scenario with two browsers
Simplify JSON scenario with two browsers
