title: No such file or directory @ rb_sysopen - tmp/pids/puma.pid
body: <p>I'm trying to start puma, but at the last step it fails like this:</p>
  
  <pre><code>16:38:09 web.1  | /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/launcher.rb:130:in `initialize': No such file or directory @ rb_sysopen - tmp/pids/puma.pid (Errno::ENOENT)
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/launcher.rb:130:in `open'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/launcher.rb:130:in `write_pid'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/launcher.rb:103:in `write_state'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/single.rb:92:in `run'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/launcher.rb:174:in `run'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/lib/puma/cli.rb:77:in `run'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/gems/puma-3.9.1/bin/puma:10:in `&lt;top (required)&gt;'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/bin/puma:23:in `load'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/bin/puma:23:in `&lt;main&gt;'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/bin/ruby_executable_hooks:15:in `eval'
  16:38:09 web.1  |   from /home/ramonpm/.rvm/gems/ruby-2.2.7/bin/ruby_executable_hooks:15:in `&lt;main&gt;'
  16:38:09 web.1  | exited with code 1
  16:38:09 system | sending SIGTERM to all processes
  </code></pre>
  
  <p>Couldn't find a solution somewhere else, they are all related to different things.</p>