我现在跟随Heroku instructions以及another deploy tutorial。当我运行heroku local并且网站看起来很好时，我能够在本地运行应用程序。然后我去heroku open，我得到System Error (500)
我的问题是：a）如何阅读这些日志以确定错误，以及b）当本地应用程序运行正常但在尝试通过Heroku应用程序打开时出现服务器错误时的其他一些故障排除？谢谢你的帮助。
这是来自heroku logs
2016-09-21T22:14:22.183850+00:00 heroku[web.1]: Starting process with command `gunicorn aptly.wsgi`
2016-09-21T22:14:25.965426+00:00 app[web.1]: [2016-09-21 22:14:25 +0000] [3] [INFO] Starting gunicorn 19.6.0
2016-09-21T22:14:26.018518+00:00 app[web.1]: [2016-09-21 22:14:26 +0000] [3] [INFO] Listening at: http://0.0.0.0:6663 (3)
2016-09-21T22:14:26.018676+00:00 app[web.1]: [2016-09-21 22:14:26 +0000] [3] [INFO] Using worker: sync
2016-09-21T22:14:26.023706+00:00 app[web.1]: [2016-09-21 22:14:26 +0000] [7] [INFO] Booting worker with pid: 7
2016-09-21T22:14:26.092715+00:00 app[web.1]: [2016-09-21 22:14:26 +0000] [8] [INFO] Booting worker with pid: 8
2016-09-21T22:14:26.764197+00:00 heroku[web.1]: State changed from starting to up
2016-09-21T22:15:02.410363+00:00 heroku[router]: at=info method=GET path="/" host=desolate-cove-94597.herokuapp.com request_id=53f43d4a-5b5c-477b-a355-39bf5156f8b3 fwd="73.163.191.79" dyno=web.1 connect=1ms service=223ms status=500 bytes=239
2016-09-21T22:15:28.285891+00:00 heroku[api]: Starting process with command `python manage.py migrate` by me@gmail.com
2016-09-21T22:15:41.534684+00:00 heroku[run.7412]: Awaiting client
2016-09-21T22:15:41.555107+00:00 heroku[run.7412]: Starting process with command `python manage.py migrate`
2016-09-21T22:15:41.801070+00:00 heroku[run.7412]: State changed from starting to up
2016-09-21T22:15:44.353920+00:00 heroku[run.7412]: State changed from up to complete
2016-09-21T22:15:44.329626+00:00 heroku[run.7412]: Process exited with status 0
2016-09-21T22:16:03.086299+00:00 heroku[api]: Starting process with command `python manage.py createsuperuser` by me@gmail.com
2016-09-21T22:16:12.065178+00:00 heroku[run.2986]: Awaiting client
2016-09-21T22:16:12.211145+00:00 heroku[run.2986]: State changed from starting to up
2016-09-21T22:16:12.115569+00:00 heroku[run.2986]: Starting process with command `python manage.py createsuperuser`
2016-09-21T22:16:47.426556+00:00 heroku[run.2986]: State changed from up to complete
2016-09-21T22:16:47.417258+00:00 heroku[run.2986]: Process exited with status 0
2016-09-21T22:17:29.613811+00:00 heroku[router]: at=info method=GET path="/" host=desolate-cove-94597.herokuapp.com request_id=139eb23c-3c5c-4a0d-a39d-bdcef078c5ab fwd="73.163.191.79" dyno=web.1 connect=2ms service=278ms status=500 bytes=239
2016-09-21T22:25:20.701742+00:00 heroku[api]: Starting process with command `python manage.py migrate` by me@gmail.com
2016-09-21T22:25:29.863579+00:00 heroku[run.1764]: Awaiting client
2016-09-21T22:25:29.892630+00:00 heroku[run.1764]: Starting process with command `python manage.py migrate`
2016-09-21T22:25:30.117446+00:00 heroku[run.1764]: State changed from starting to up
2016-09-21T22:25:32.716060+00:00 heroku[run.1764]: Process exited with status 0
2016-09-21T22:25:32.732441+00:00 heroku[run.1764]: State changed from up to complete
2016-09-21T22:26:29.724389+00:00 heroku[router]: at=info method=GET path="/" host=desolate-cove-94597.herokuapp.com request_id=7dc56798-101e-4e89-b4d6-5b892c2175c8 fwd="73.163.191.79" dyno=web.1 connect=1ms service=219ms status=500 bytes=239