Make "nohup" non-default optional to address 9z0b3t1c#101

The interaction between this gem and capistrano-rbenv causes problems in this configuration. Allowing "nohup" to be left out is a workaround. See 9z0b3t1c#101 for why this is so.

lib/capistrano-resque/capistrano_integration.rb

@@ -50,7 +50,7 @@ def start_command(queue, pid)
            PIDFILE=#{pid} BACKGROUND=yes \
            #{"VERBOSE=1 " if fetch(:resque_verbose)}\
            INTERVAL=#{interval} \
-           nohup #{fetch(:bundle_cmd, "bundle")} exec rake \
+           #{fetch(:nohup_cmd, "")} #{fetch(:bundle_cmd, "bundle")} exec rake \
            #{"environment " if fetch(:resque_environment_task)}\
            resque:work #{output_redirection}"
         end
@@ -82,7 +82,7 @@ def start_scheduler(pid)
            #{"VERBOSE=1 " if fetch(:resque_verbose)}\
            MUTE=1 \
            #{"DYNAMIC_SCHEDULE=yes " if fetch(:resque_dynamic_schedule)}\
-           nohup #{fetch(:bundle_cmd, "bundle")} exec rake \
+           #{fetch(:nohup_cmd, "")} #{fetch(:bundle_cmd, "bundle")} exec rake \
            #{"environment " if fetch(:resque_environment_task)}\
            resque:scheduler #{output_redirection}"
         end