Supply app context for Scheduler scripts that (should) populate the DB

[Kate Manning]

Logs from heroku show that writing to the DB is failing... seemingly because we're using the app factory pattern and then not supplying an app context to the scripts:

2019-02-22T14:10:53.041778+00:00 app[api]: Starting process with command `python3 bin/get_count.py needsdiagnosis` by user [e-mail]
2019-02-22T14:10:57.894234+00:00 heroku[scheduler.5408]: Starting process with command `python3 bin/get_count.py needsdiagnosis`
2019-02-22T14:10:58.546657+00:00 heroku[scheduler.5408]: State changed from starting to up
2019-02-22T14:11:06.721387+00:00 app[scheduler.5408]: Traceback (most recent call last):
2019-02-22T14:11:06.721415+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/_collections.py", line 999, in __call__
2019-02-22T14:11:06.722549+00:00 app[scheduler.5408]:     return self.registry[key]
2019-02-22T14:11:06.724908+00:00 app[scheduler.5408]: KeyError: 140529743968000
2019-02-22T14:11:06.724942+00:00 app[scheduler.5408]:
2019-02-22T14:11:06.724944+00:00 app[scheduler.5408]: During handling of the above exception, another exception occurred:
2019-02-22T14:11:06.724946+00:00 app[scheduler.5408]:
2019-02-22T14:11:06.724980+00:00 app[scheduler.5408]: Traceback (most recent call last):
2019-02-22T14:11:06.725016+00:00 app[scheduler.5408]:   File "bin/get_count.py", line 114, in <module>
2019-02-22T14:11:06.725301+00:00 app[scheduler.5408]:     sys.exit(main())
2019-02-22T14:11:06.725443+00:00 app[scheduler.5408]:   File "bin/get_count.py", line 95, in main
2019-02-22T14:11:06.725870+00:00 app[scheduler.5408]:     db.session.add(iss_count)
2019-02-22T14:11:06.726170+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/orm/scoping.py", line 153, in do
2019-02-22T14:11:06.726422+00:00 app[scheduler.5408]:     return getattr(self.registry(), name)(*args, **kwargs)
2019-02-22T14:11:06.729346+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/_collections.py", line 1001, in __call__
2019-02-22T14:11:06.730089+00:00 app[scheduler.5408]:     return self.registry.setdefault(key, self.createfunc())
2019-02-22T14:11:06.730130+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2950, in __call__
2019-02-22T14:11:06.731946+00:00 app[scheduler.5408]:     return self.class_(**local_kw)
2019-02-22T14:11:06.741327+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_sqlalchemy/__init__.py", line 141, in __init__
2019-02-22T14:11:06.741689+00:00 app[scheduler.5408]:     self.app = app = db.get_app()
2019-02-22T14:11:06.741728+00:00 app[scheduler.5408]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask_sqlalchemy/__init__.py", line 912, in get_app
2019-02-22T14:11:06.742502+00:00 app[scheduler.5408]:     'No application found. Either work inside a view function or push'
2019-02-22T14:11:06.744062+00:00 app[scheduler.5408]: RuntimeError: No application found. Either work inside a view function or push an application context. See http://flask-sqlalchemy.pocoo.org/contexts/