bump gunicorn version to fix server issue
bump gunicorn version to fix server issue

jfterpstra/bluebottle,onepercentclub/bluebottle,onepercentclub/bluebottle,jfterpstra/bluebottle,jfterpstra/bluebottle,onepercentclub/bluebottle,onepercentclub/bluebottle,onepercentclub/bluebottle,jfterpstra/bluebottle