fix: package.json and lock file was not synced, the lock file has been updated now.

documentation/CI.md

@@ -25,9 +25,6 @@ This is important because `npm` uses the pinned dependencies in your `package-lo
 
 However, when these changes surface within a CI build, this indicates differing dependency expectations between the committed `package.json` file and the `package-lock.json` file, which is a good reason to fail a build.
 
-### What is this `npm run is-es5` check?
-
-This project outputs production files to the `dist` folder. The `npm script`, `npm run is-es5`, checks the JavaScript files in the `dist` folder to make sure that they are `ES5`-compliant.
 
 This check is important because `ES5` JavaScript has [greater browser compatibility](http://kangax.github.io/compat-table/es5/) than [`ES2015+`](http://kangax.github.io/compat-table/es6/) - particularly for `IE11`.
 

package.json

@@ -72,7 +72,6 @@
     "axios-mock-adapter": "^1.17.0",
     "codecov": "^3.6.1",
     "enzyme-adapter-react-16": "^1.14.0",
-    "es-check": "^2.3.0",
     "fetch-mock": "^6.5.2",
     "husky": "2.7.0",
     "identity-obj-proxy": "^3.0.0",