Need help with Active Record

Help please!
1.Bundles are installed
2.When I do “rake db:migrate”, it says "cannot load such file – sinatra/activerecord
3.When I do “bundle exec rake rake db:migrate”, it says nothing

#app.rb
#подключаем нужные библиотеки
require ‘sinatra’
require ‘rubygems’
require ‘sinatra/reloader’
require ‘sqlite3’
require ‘sinatra/activerecord’

set :database, "sqlite3:bs.db"

class Client < ActiveRecord::Base
end

class Master < ActiveRecord::Base
end

get '/' do
  erb '<h1>Hello my dear friend</h1>'
end

#Rakefile
require “./app”
require “sinatra/activerecord/rake”

#Gemfile
source ‘https://rubygems.org

gem 'sinatra'
gem 'sqlite3'
gem 'activerecord'
gem 'sinatra-activerecord'
gem 'sinatra-contrib'
gem 'rake'

group :development do
  gem "tux"
end