disable gunicorn access logs

they're turning up in syslog, which means they're getting into kibana now

also move config settings from manifest to gunicorn_config.py

gunicorn_config.py

@@ -1,6 +1,13 @@
+import os
 import sys
 import traceback
 
+workers = 5
+worker_class = "eventlet"
+errorlog = "/home/vcap/logs/gunicorn_error.log"
+bind = "0.0.0.0:{}".format(os.getenv("PORT"))
+disable_redirect_access_to_syslog = True
+
 
 def worker_abort(worker):
     worker.log.info("worker received ABORT")