deploy: fix after_party deployment

This can be tested locally (without running any SSH commands) using:

```shell
bundle exec mina deploy domain="test.domain" to=production --simulate`
```

This commit turns the after_party command from:

```
cd "/var/www/tps/current" && RAILS_ENV="production" bundle exec rake after_party:run
```

to:

```
RAILS_ENV="production" bundle exec rake after_party:run
```

which is more in line with how other commands are run.

config/deploy.rb

@@ -104,6 +104,16 @@ namespace :yarn do
   end
 end
 
+namespace :after_party do
+  desc "Run after_party tasks."
+  task :run do
+    queue %{
+      echo "-----> Running deploy tasks"
+      #{echo_cmd %[#{rake} after_party:run]}
+    }
+  end
+end
+
 desc "Deploys the current version to the server."
 task :deploy => :environment do
   queue 'export PATH=$PATH:/usr/local/rbenv/bin:/usr/local/rbenv/shims'
@@ -116,7 +126,7 @@ task :deploy => :environment do
     invoke :'bundle:install'
     invoke :'yarn:install'
     invoke :'rails:db_migrate'
-    invoke :'rake[after_party:run]'
+    invoke :'after_party:run'
     invoke :'rails:assets_precompile:force'
 
     to :launch do