Improve linting

.eslintrc

@@ -1,10 +1,15 @@
 {
+  "extends": "eslint:recommended",
   "parserOptions": {
     "ecmaVersion": 2017,
     "ecmaFeatures": {
       "experimentalObjectRestSpread": true
     }
   },
+  "env": {
+    "node": true,
+    "es6": true
+  },
   "plugins": [
     "prettier"
   ],

__tests__/validate-title.js

@@ -4,6 +4,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+/* eslint-env jest */
+
 const t = require('assert');
 
 const isValidTitle = require('../validate-title.js');

index.js

@@ -11,6 +11,7 @@ module.exports = robot => {
   robot.on('pull_request.edited', check);
 
   async function check(context) {
+    const pr = context.payload.pull_request;
     const passed = isValidTitle(pr.title);
     setStatus(context, passed);
   }

package.json

@@ -13,7 +13,7 @@
   },
   "dependencies": {
     "compromise": "^10.7.2",
-    "probot": "^0.11.0"
+    "probot": "^3.0.0"
   },
   "devDependencies": {
     "eslint": "^4.8.0",