upgrade eslint

Author: ele828

package.json

@@ -16,7 +16,7 @@
     "@babel/plugin-proposal-class-properties": "^7.5.5",
     "@babel/preset-env": "^7.5.5",
     "babel-loader": "^8.0.6",
-    "eslint": "^3.19.0",
+    "eslint": "^4.18.2",
     "eslint-friendly-formatter": "^2.0.6",
     "eslint-loader": "^1.5.0",
     "eslint-plugin-jest": "^20.0.3",