update supported browsers and add a few more

Now includes Firefox ESR, Opera and a few more browser with usages
between 0.5% and 1%. defaults resolves to > 0.5%, last 2 versions, Firefox ESR, not dead.

Author: silverwind

package.json

@@ -28,9 +28,6 @@
     "webpack-cli": "3.3.10"
   },
   "browserslist": [
-    "> 1%",
-    "last 2 firefox versions",
-    "last 2 safari versions",
-    "ie 11"
+    "defaults"
   ]
 }