Change how we start puma

Puma is integrated with rails server, no need to start it manually.
Takes care of logging etc. We also shouldn't run multiple workers
unless we absolutely want to.

Procfile

@@ -1,2 +1,2 @@
-web: bundle exec puma -C config/puma.rb
+web: bundle exec rails server -b 0.0.0.0
 worker: bundle exec rails jobs:work

config/puma.rb

@@ -21,7 +21,7 @@ environment ENV.fetch("RAILS_ENV") { "development" }
 # Workers do not work on JRuby or Windows (both of which do not support
 # processes).
 #
-workers ENV.fetch("WEB_CONCURRENCY") { 2 }
+workers ENV.fetch("WEB_CONCURRENCY") { 1 }
 
 # Use the `preload_app!` method when specifying a `workers` number.
 # This directive tells Puma to first boot the application and load code