title: Ask Capistrano to run a task before it linked(symlink) a file
body: <p>I been trying to write a capistrano script where I have copy config file from the my application directory(<code>support/config/#{rails_env}</code>) to the <code>shared directory</code>(shared/config) in capistrano  </p>
  
  <p><code>rails_env =&gt; 'staging'</code></p>
  
  <p>So that when the capistrano run the <code>first time</code> it sort copies the file from the <code>support/config/#{rails_env}</code> directory to shared/config directory but it need to run it before the file is linked by capistrano i.e before this is done</p>
  
  <p><code>set :linked_files, %w{config/api_config.yml}</code></p>
  
  <p>so that the linked task doesnot fail (since it require the task required the file to be present in shared directory)</p>
  
  <p>Here is my Capfile (Nothing fancy since most of the stuff is done my capistrno)</p>
  
  <pre><code>set :application, 'custom-api'
  set :repo_url, ''
  
  # ask :branch, proc { `git rev-parse --abbrev-ref HEAD`.chomp }
  set :rails_env, 'staging' 
  set :deploy_to, '/var/apps/staging/custom-api'
  set :scm, :git
  
  set :format, :pretty
  set :log_level, :debug
  set :rvm_type, :user   # Defaults to: :auto
  set :rvm_ruby_version, 'ruby-1.9.3@484@custom-api'  
  #set :rvm_custom_path, '~/.myveryownrvm'  # only needed if not detected
  # set :pty, true
  set :linked_files, %w{config/mongoid.yml config/api_config.yml}
  set :linked_dirs, %w{bin log tmp/pids tmp/cache tmp/sockets vendor/bundle public/system}
  
  #set :default_env, { path: "$HOME/.rvm/#{}:$PATH" }
  set :keep_releases, 5
  #SSHKit.config.command_map[:cp_r]  = "cp -r"
  
  ## Need to run before the file is linked
  #before 'deploy:[task_name]' , 'deploy:copy_files'
  
  namespace :deploy do
    desc 'Copy files from application to shared directory'
    ## copy the files to the shared directories
    task :copy_files do 
      on roles(:app) do
        execute :cp ,'-r',release_path.join('support/config'),shared_path
      end  
    end
  
    desc 'Restart application'
    task :restart do
      on roles(:app), in: :sequence, wait: 5 do
        # Your restart mechanism here, for example:
        execute :touch, release_path.join('tmp/restart.txt')
      end
    end
  
    after :restart, :clear_cache do
      on roles(:web), in: :groups, limit: 3, wait: 10 do
        # Here we can do anything such as:
        # within release_path do
        #   execute :rake, 'cache:clear'
        # end
      end
    end
    after :finishing, 'deploy:cleanup'
  end
  </code></pre>
  
  <p>All I need is to do something like </p>
  
  <p><code>before 'deploy:[task_name]' , 'deploy:copy_files'</code></p>
  
  <p>Added Note : Using Capistrno 3.0.1 </p>