JSDOM only supports Node 6 and up so that's all we can support

.travis.yml

@@ -2,7 +2,6 @@ language: node_js
 node_js:
   - '8'
   - '6'
-  - '4'
 script: npm test
 after_success: npm run coverage
 notifications:

src/index.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const JSDOM = require('jsdom').JSDOM;
+const { JSDOM } = require('jsdom');
 
 // Class to return a window instance.
 // Accepts a jsdom config object.