add rate service

lib/data/provider/auth_fb.dart

@@ -132,6 +132,8 @@ class AuthFb {
     String privileges = idToken.claims["pr"];
     if (privileges != null && privileges != "") {
       user.privileges = privileges.split(":").toList();
+    } else {
+      user.privileges = [];
     }
     controller.add(user);
   }
@@ -198,18 +200,6 @@ class AuthFb {
     return token.token;
   }
 
-  Future<Setting> getSetting() async {
-    var snap = await Firestore.instance
-        .collection(config_collection)
-        .document(setting_doc_id)
-        .get();
-    if (!snap.exists) {
-      return null;
-    }
-    // _listSetting();
-    return Setting.fromMap(snap.data);
-  }
-
   Stream<Setting> settings() async* {
     Stream<DocumentSnapshot> snapshot = Firestore.instance
         .collection(config_collection)