added baidu tongji for analytics

frontend/src/store/modules/stats.js

@@ -0,0 +1,14 @@
+const state = {}
+const getters = {
+  useStats () {
+    return localStorage.getItem('useStats')
+  }
+}
+const mutations = {}
+const actions = {}
+export default {
+  state,
+  getters,
+  mutations,
+  actions
+}