Takes the gamble that QUnit is a development dependency of Three (update 1.18.0 to 2.1.1)

package.json

@@ -48,6 +48,7 @@
   "devDependencies": {
     "eslint": "^3.10.1",
     "eslint-config-mdcs": "^4.2.2",
+    "qunitjs": "^2.1.1",
     "rollup": "^0.36.3",
     "rollup-watch": "^2.5.0",
     "uglify-js": "^2.6.0"