chore: remove standard

ESLint is used directly.

package.json

@@ -39,14 +39,9 @@
   },
   "devDependencies": {
     "babel": "^5.8.34",
-    "babel-eslint": "^4.1.6",
     "eslint": "^5.0.1",
     "prettier": "^1.13.7",
-    "source-map-support": "^0.4.0",
-    "standard": "^5.4.1"
-  },
-  "standard": {
-    "parser": "babel-eslint"
+    "source-map-support": "^0.4.0"
   },
   "license": "MIT"
 }