Why doesn't bundle exec rake work?

gistfile1.txt

saasbook@saasbook:~$ cd Documents/hw2_rottenpotatoes/
saasbook@saasbook:~/Documents/hw2_rottenpotatoes$ bundle install --without production
Using rake (0.9.2.2) 
Using multi_json (1.0.4) 
Using activesupport (3.1.0) 
Using bcrypt-ruby (3.0.1) 
Using builder (3.0.0) 
Using i18n (0.6.0) 
Using activemodel (3.1.0) 
Using erubis (2.7.0) 
Using rack (1.3.5) 
Using rack-cache (1.0.3) 
Using rack-mount (0.8.3) 
Using rack-test (0.6.1) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.0.3) 
Using actionpack (3.1.0) 
Using mime-types (1.17.2) 
Using polyglot (0.3.3) 
Using treetop (1.4.10) 
Using mail (2.3.0) 
Using actionmailer (3.1.0) 
Using arel (2.2.1) 
Using tzinfo (0.3.31) 
Using activerecord (3.1.0) 
Using activeresource (3.1.0) 
Using archive-tar-minitar (0.5.2) 
Using coffee-script-source (1.2.0) 
Using execjs (1.2.13) 
Using coffee-script (2.2.0) 
Using rack-ssl (1.3.2) 
Using json (1.6.3) 
Using rdoc (3.12) 
Using thor (0.14.6) 
Using railties (3.1.0) 
Using coffee-rails (3.1.1) 
Using columnize (0.3.5) 
Using haml (3.1.4) 
Using jquery-rails (1.0.19) 
Using libv8 (3.3.10.4) 
Using ruby_core_source (0.1.5) 
Using linecache19 (0.5.12) 
Using bundler (1.1.5) 
Using rails (3.1.0) 
Using ruby-debug-base19 (0.11.25) 
Using ruby-debug19 (0.11.6) 
Using sass (3.1.12) 
Using sass-rails (3.1.5) 
Using sqlite3 (1.3.5) 
Using therubyracer (0.9.9) 
Using uglifier (1.2.2) 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.
saasbook@saasbook:~/Documents/hw2_rottenpotatoes$ rake db:migrate
rake aborted!
You have already activated rake 10.0.4, but your Gemfile requires rake 0.9.2.2. Using bundle exec may solve this.
/home/ubuntu/Documents/hw2_rottenpotatoes/config/boot.rb:6:in `<top (required)>'
/home/ubuntu/Documents/hw2_rottenpotatoes/config/application.rb:1:in `<top (required)>'
/home/ubuntu/Documents/hw2_rottenpotatoes/Rakefile:5:in `<top (required)>'
(See full trace by running task with --trace)
saasbook@saasbook:~/Documents/hw2_rottenpotatoes$ bundle exec rake
rake aborted!
Don't know how to build task 'test'

Tasks: TOP => default
(See full trace by running task with --trace)