Added description to the Capistrano task

So that the task is visible in "cap -T"

lib/capistrano/tasks/rails_tail_log.rake

@@ -1,4 +1,5 @@
 namespace :rails do
+  desc "Tail rails logs from server"
   task :tail_log do
     on roles(:app) do
       execute "tail -f #{shared_path}/log/#{fetch(:rails_env)}.log"