Reload Unicorn and Sidekiq after deployment

So we can remove the following manual step from the deployment process:

> There is one last step though. Until we don't fix it, the app server
needs to be restarted manually for the changes to be loaded. Run:

> $ ssh timeoverflow@www.timeoverflow.org
> $ sudo systemctl restart timeoverflow
> $ sudo systemctl restart sidekiq

Now the Capistrano output looks like:

```
INFO [fbff0613] Running /usr/bin/env rm -rf /var/www/timeoverflow/releases/20191220151536 as timeoverflow@staging.timeoverflow.org
DEBUG [fbff0613] Command: ( export RBENV_ROOT="$HOME/.rbenv" RBENV_VERSION="" ; /usr/bin/env rm -rf /var/www/timeoverflow/releases/20191220151536 )
 INFO [fbff0613] Finished in 0.183 seconds with exit status 0 (successful).
 INFO [9ab57c12] Running sudo systemctl reload timeoverflow as timeoverflow@staging.timeoverflow.org
DEBUG [9ab57c12] Command: sudo systemctl reload timeoverflow
 INFO [9ab57c12] Finished in 0.218 seconds with exit status 0 (successful).
 INFO [41e063eb] Running sudo systemctl restart sidekiq as timeoverflow@staging.timeoverflow.org
DEBUG [41e063eb] Command: sudo systemctl restart sidekiq
 INFO [41e063eb] Finished in 2.895 seconds with exit status 0 (successful).
DEBUG [3772e021] Running if test ! -d /var/www/timeoverflow/releases; then echo "Directory does not exist '/var/www/timeoverflow/releases'" 1>&2; false; fi as timeoverflow@staging.timeoverflow.org
DEBUG [3772e021] Command: if test ! -d /var/www/timeoverflow/releases; then echo "Directory does not exist '/var/www/timeoverflow/releases'" 1>&2; false; fi
DEBUG [3772e021] Finished in 0.181 seconds with exit status 0 (successful).
 INFO [266848f2] Running echo "Branch reload-unicorn-after-deployment (at fad9dbd) deployed as release 20191220152039 by pau" >> /var/www/timeoverflow/revisions.log as timeoverflow@staging.timeoverflow.org
DEBUG [266848f2] Command: echo "Branch reload-unicorn-after-deployment (at fad9dbd) deployed as release 20191220152039 by pau" >> /var/www/timeoverflow/revisions.log
 INFO [266848f2] Finished in 0.181 seconds with exit status 0 (successful).
```

Which generates the following log line

```
==> log/unicorn.err.log <==
E, [2019-12-20T16:20:59.911297 #32630] ERROR -- : reexec-ed child already running PID:1213
```

Author: sauloperez

config/deploy.rb

@@ -47,13 +47,20 @@
 # Default value for keep_releases is 5
 # set :keep_releases, 5
 
-namespace :deploy do
-  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
+namespace :unicorn do
+  desc 'reload Unicorn'
+  task :reload do
+    on roles(:app) do
+      execute "sudo systemctl reload timeoverflow"
+    end
+  end
+end
+
+namespace :sidekiq do
+  desc 'reload Sidekiq'
+  task :restart do
+    on roles(:app) do
+      execute "sudo systemctl restart sidekiq"
     end
   end
 end
@@ -67,4 +74,8 @@
     end
   end
 end
+
 before "deploy:migrate", "deploy:db:load" if ENV["COLD"]
+
+after "deploy:finishing", "unicorn:reload"
+after "deploy:finishing", "sidekiq:restart"