title: Gitlab with mysql2 gem after upgrading to 7.0
body: <p>I have problem with mysql2 gem after upgrading my Gitlab to version 7.0 here is my error log what can i do to fix it?</p>
  
  <pre><code>I, [2014-06-24T06:49:07.574760 #18301]  INFO -- : Refreshing Gem list
  /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:190:in `rescue in spec': Specified 'mysql2' for database adapter, but the gem is not loaded. Add `gem 'mysql2'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord). (Gem::LoadError)
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/connection_specification.rb:187:in `spec'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_handling.rb:50:in `establish_connection'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/railtie.rb:129:in `block (2 levels) in &lt;class:Railtie&gt;'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/lazy_load_hooks.rb:27:in `each'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.1/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/railtie.rb:118:in `block in &lt;class:Railtie&gt;'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/initializable.rb:30:in `instance_exec'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/initializable.rb:30:in `run'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/initializable.rb:55:in `block in run_initializers'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:180:in `each'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
      from /usr/local/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/initializable.rb:54:in `run_initializers'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/application.rb:288:in `initialize!'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/railtie.rb:194:in `public_send'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/railties-4.1.1/lib/rails/railtie.rb:194:in `method_missing'
      from /home/git/gitlab/config/environment.rb:5:in `&lt;top (required)&gt;'
      from config.ru:13:in `require'
      from config.ru:13:in `block in &lt;main&gt;'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
      from config.ru:1:in `new'
      from config.ru:1:in `&lt;main&gt;'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/lib/unicorn.rb:48:in `eval'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/lib/unicorn.rb:48:in `block in builder'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/bin/unicorn_rails:139:in `call'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/bin/unicorn_rails:139:in `block in rails_builder'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/lib/unicorn/http_server.rb:722:in `call'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/lib/unicorn/http_server.rb:722:in `build_app!'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/lib/unicorn/http_server.rb:140:in `start'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/gems/unicorn-4.6.3/bin/unicorn_rails:209:in `&lt;top (required)&gt;'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/bin/unicorn_rails:23:in `load'
      from /home/git/gitlab/vendor/bundle/ruby/2.0.0/bin/unicorn_rails:23:in `&lt;main&gt;'
  </code></pre>