Update standard to v13

Author: goto-bus-stop

package.json

@@ -21,7 +21,7 @@
     "acorn-static-class-features": "^0.2.0",
     "buble": "^0.19.7",
     "mkdirp": "^0.5.1",
-    "standard": "^12.0.1",
+    "standard": "^13.1.0",
     "tape": "^4.11.0"
   },
   "homepage": "https://github.com/browserify/acorn-node",