<NME> testem.js
<BEF> module.exports = {
  "test_page": "tests/index.html",
  "disable_watching": true,
  "launch_in_ci": [
    "PhantomJS"
  ],
  "launch_in_dev": [
    "PhantomJS",
    "Chrome"
  ]
};
      ].filter(Boolean)
    }
  }
};

<MSG> Use headless Chrome instead of PhantomJS

<DFF> @@ -1,11 +1,21 @@
 module.exports = {
-  "test_page": "tests/index.html",
-  "disable_watching": true,
-  "launch_in_ci": [
-    "PhantomJS"
+  test_page: 'tests/index.html?hidepassed',
+  disable_watching: true,
+  launch_in_ci: [
+    'Chrome'
   ],
-  "launch_in_dev": [
-    "PhantomJS",
-    "Chrome"
-  ]
+  launch_in_dev: [
+    'Chrome'
+  ],
+  browser_args: {
+    Chrome: {
+      mode: 'ci',
+      args: [
+        '--disable-gpu',
+        '--headless',
+        '--remote-debugging-port=0',
+        '--window-size=1440,900'
+      ]
+    }
+  }
 };

Use headless Chrome instead of PhantomJS