Issue 6717 - Part 1: run eslint through npm

package.json

Index: package.json
===================================================================
new file mode 100644
--- /dev/null
+++ b/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "adblockpluschrome",
+  "repository": "https://hg.adblockplus.org/adblockpluschrome",
+  "license": "GPL-3.0",
+  "dependencies": {},
+  "devDependencies": {
+    "eslint": "^4.19.0",

[Sebastian Noack, 2018/07/13 15:04:08]

We want to update to ESLint 5, don't we? Moreover, is it even necessary to
redundantly specify the eslint version here, since it's already given as
peerDependency in eslint-config-eyeo?

[hub, 2018/07/13 15:05:47]

I have moved on to ^5.1.0.
When the peerDependency in eslint-config-eyeo, we can ditch it here.

[Sebastian Noack, 2018/07/13 15:08:26]

Let's update eslint-config-eyeo [1] first, so that we don't need to change the
configuration here twice.

[1]: https://hg.adblockplus.org/codingtools/file/master/eslint-config-eyeo

[hub, 2018/07/13 16:12:43]

Acknowledged.

[Sebastian Noack, 2018/08/14 19:16:55]

What is about this comment?

[hub, 2018/08/14 19:35:16]

it is needed. Without it, I get:

````
$ npm install
added 1 package in 0.648s
[ no eslint installed ]
$ npm install
npm WARN eslint-config-eyeo@2.1.0 requires a peer of eslint@^5.1 but none was
installed.

up to date in 0.083s
````

If I add it, all is good.

+    "eslint-config-eyeo": "2.0.0"
+  },
+  "scripts": {
+    "lint": "eslint *.js lib/ qunit/ ext/",
+    "posttest": "npm run lint"
+  }
+}