title: Gem::LoadError: Specified 'postgresql' for database adapter, but the gem is not loaded
body: <p>Help me! Enter "mina deploy" get this beauty:</p>
  
  <p>My "/home/deploy/inscope/shared/config/database.yml" looks:</p>
  
  <pre><code>production:
    adapter: postgresql
    encoding: unicode
    database: ***
    username: ***
    password: ***
    host: localhost
  
  rake aborted!
     Gem::LoadError: Specified 'postgresql' for database adapter, but the gem is not loaded. Add `gem 'pg'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord).
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_adapters/connection_specification.rb:190:in `rescue in spec'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_adapters/connection_specification.rb:187:in `spec'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_handling.rb:50:in `establish_connection'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/railtie.rb:129:in `block (2 levels) in &lt;class:Railtie&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:27:in `each'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/railtie.rb:118:in `block in &lt;class:Railtie&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:30:in `instance_exec'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:30:in `run'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:55:in `block in run_initializers'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:54:in `run_initializers'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:288:in `initialize!'
     /home/deploy/inscope/tmp/build-142737137923106/config/environment.rb:5:in `&lt;top (required)&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `block in require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:232:in `load_dependency'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:264:in `require_environment!'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:367:in `block in run_tasks_blocks'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-2.2.4/lib/sprockets/rails/task.rb:64:in `block (2 levels) in define'
     Gem::LoadError: pg is not part of the bundle. Add it to Gemfile.
     /home/deploy/.rvm/gems/ruby-2.2.0/gems/bundler-1.9.1/lib/bundler/rubygems_integration.rb:261:in `block in replace_gem'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_adapters/postgresql_adapter.rb:13:in `&lt;top (required)&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `block in require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:232:in `load_dependency'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_adapters/connection_specification.rb:188:in `spec'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/connection_handling.rb:50:in `establish_connection'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/railtie.rb:129:in `block (2 levels) in &lt;class:Railtie&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:27:in `each'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activerecord-4.1.0/lib/active_record/railtie.rb:118:in `block in &lt;class:Railtie&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:30:in `instance_exec'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:30:in `run'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:55:in `block in run_initializers'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/initializable.rb:54:in `run_initializers'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:288:in `initialize!'
     /home/deploy/inscope/tmp/build-142737137923106/config/environment.rb:5:in `&lt;top (required)&gt;'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `block in require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:232:in `load_dependency'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/activesupport-4.1.0/lib/active_support/dependencies.rb:247:in `require'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:264:in `require_environment!'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/railties-4.1.0/lib/rails/application.rb:367:in `block in run_tasks_blocks'
     /home/deploy/inscope/tmp/build-142737137923106/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-2.2.4/lib/sprockets/rails/task.rb:64:in `block (2 levels) in define'
     Tasks: TOP =&gt; environment
     (See full trace by running task with --trace)
  </code></pre>
  
  <p>!     ERROR: Deploy failed.<br>
  -----> Cleaning up build<br>
         Unlinking current 
         OK </p>
  
  <p>!     Command failed.
         Failed with status 19</p>