Update Unicorn config

config/unicorn.rb

 # TODO (rspeicher): Change path
-@dir = "/path/to/app/"
+dir = "/path/to/app/"
 
 worker_processes 2
-working_directory @dir
+working_directory dir
 
 timeout 30
 
-listen "#{@dir}tmp/sockets/unicorn.sock", backlog: 64
+listen File.join(dir, %w(tmp sockets unicorn.sock)), backlog: 64
 
-pid "#{@dir}tmp/pids/unicorn.pid"
+pid File.join(dir, %w(tmp pids unicorn.pid))
 
-stderr_path "#{@dir}log/unicorn.stderr.log"
-stdout_path "#{@dir}log/unicorn.stdout.log"
+stderr_path File.join(dir, %w(log unicorn.stderr.log))
+stdout_path File.join(dir, %w(log unicorn.stdout.log))