title: Error with Vue.use(Vuex) Typescript
body: <p>I have used npm to install both vue (2.4.2) and vuex (2.3.1).  When I try to compile the below code I get the error:</p>
  
  <p><a href="https://i.stack.imgur.com/0ZKgE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0ZKgE.png" alt="enter image description here"></a></p>
  
  <h2>Store.ts</h2>
  
  <pre><code>import Vue from 'vue';
  import Vuex from 'vuex';
  
  Vue.use(Vuex);  // Error is thrown here
  
  export default new Vuex.Store({
    // store here
  })
  </code></pre>
  
  <h2>tsconfig.json</h2>
  
  <pre><code>{
    "compilerOptions": {
      "allowSyntheticDefaultImports": true,
      "experimentalDecorators": true,
      "lib": [
        "es2015",
        "dom",
        "es2015.promise"
      ],
      "module": "es2015",
      "moduleResolution": "node",
      "noImplicitAny": false,
      "removeComments": false,
      "sourceMap": true,
      "target": "es5"
  
    },
    "exclude": [
      "./node_modules",
      "wwwroot",
      "./Model"
    ],
    "include": [
      "./CCSEQ",
      "./WebResources",
      "./sfc.d.ts"
    ]
  }
  </code></pre>
  
  <p>I have seen <a href="https://stackoverflow.com/questions/45459914/vuex-typescript">this</a> question, but doesn't have much helpful in it.</p>
  
  <p>Why am I getting this error and how can I resolve it?</p>