Python3.x python 错误 R10(启动超时)> Web 进程未能在启动后 60 秒内绑定到 $PORT

我正在部署一个heroku的python脚本，它将在每3 minutes次之后向另一台服务器发出请求.

部署进展顺利，但当我看到logs时，我得到了errors.

2016-11-01T07:42:12.919755+00:00 heroku[web.1]: Starting process with command `python script.py --log-file -`
2016-11-01T07:43:13.097413+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-11-01T07:43:13.097556+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-11-01T07:43:13.196156+00:00 heroku[web.1]: Process exited with status 137
2016-11-01T07:43:13.212942+00:00 heroku[web.1]: State changed from starting to crashed
2016-11-01T07:43:13.213858+00:00 heroku[web.1]: State changed from crashed to starting
2016-11-01T07:43:16.719828+00:00 heroku[web.1]: Starting process with command `python script.py --log-file -`
2016-11-01T07:44:17.215381+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2016-11-01T07:44:17.215381+00:00 heroku[web.1]: Stopping process with SIGKILL
2016-11-01T07:44:17.364708+00:00 heroku[web.1]: Process exited with status 137
2016-11-01T07:44:17.367610+00:00 heroku[web.1]: State changed from starting to crashed 

Procfile

web: python script.py --log-file -

script.py

import sys
import requests
from apscheduler.schedulers.blocking import BlockingScheduler

sched = BlockingScheduler()

@sched.scheduled_job('interval', minutes=3)
def timed_job():
    try:
        request = requests.get(url='https://royal-tag-services.herokuapp.com/api/sms-service/scheduler/')
    except Exception as e:
        print >>sys.stderr, 'scheduler request failed'

sched.start()

Result of 'tree -L 1' command

├── Procfile
├── requirements.txt
├── script.py
└── supporterenv