feat(webkit,firefox): bump versions (#3110)

Author: yury-s

browsers.json

@@ -7,11 +7,11 @@
     },
     {
       "name": "firefox",
-      "revision": "1137"
+      "revision": "1138"
     },
     {
       "name": "webkit",
-      "revision": "1308"
+      "revision": "1313"
     }
   ]
 }