Change gem active_model_serializers version

Gemfile

@@ -137,8 +137,7 @@ gem 'screencap'
 
 # using while rails 5 isn't released
 gem 'rails-api'
-gem 'active_model_serializers'
+gem 'active_model_serializers', '<=0.9'
 
 # limit the number of requests by user to api
 gem 'redis-throttle', git: 'git://github.com/lelylan/redis-throttle.git'
-