move auth into vuex state

src/store/index.js

@@ -0,0 +1,16 @@
+import Vue from 'vue';
+import Vuex from 'vuex';
+
+import authentication from './authentication';
+
+Vue.use(Vuex);
+
+const store = new Vuex.Store({
+  state: {
+  },
+  modules: {
+    authentication,
+  },
+});
+
+export default store;