Fixes minor type (#157)

* Updates documentation for testing vuex

* Fixes typo in reducing boilerplate documentation

Co-authored-by: Evert Trollip <[email protected]>

Author: everttrollip

src/reducing-boilerplate-in-tests.md

@@ -100,7 +100,7 @@ export const createStore = () => {
 // router.js
 export default new VueRouter({ ... })
 export const createRouter = () => {
-  return new Vuex.Router({ ... })
+  return new VueRouter({ ... })
 }
 ```