Fix loading rules when using Jest

req-all relies on `require.extensions` under the hood, which gets
modified by Jest, so loading rules in Jest (e.g. via ESLint Node.js API)
doesn't work, it just results in an empty object.

Since we're loading our own files, we don't need some complicated logic
to do this, we can roll our own.

index.js

@@ -1,9 +1,14 @@
 'use strict';
 
-const reqAll = require('req-all');
+const fs = require('fs');
+const path = require('path');
 const createIndex = require('create-eslint-index');
 
-const rules = reqAll('rules', {camelize: false});
+const rules = {};
+for (const file of fs.readdirSync(`${__dirname}/rules`)) {
+  const ruleName = path.basename(file, path.extname(file));
+  rules[ruleName] = require(`./rules/${ruleName}`);
+}
 
 const externalRecommendedRules = {
   'no-var': 'error'

package.json

@@ -42,8 +42,7 @@
   "dependencies": {
     "create-eslint-index": "^1.0.0",
     "eslint-ast-utils": "^1.0.0",
-    "lodash": "^4.13.1",
-    "req-all": "^0.1.0"
+    "lodash": "^4.13.1"
   },
   "devDependencies": {
     "ava": "^0.17.0",