text: Title: peloton_auto_bookmark_metric is an invalid keyword argument for athlete
  Body: Hi! Having some trouble getting started. I've pulled the latest image from dockerhub, but the container is crashing:
  
  ~/$ docker run -e MODULE_NAME=src.fitly.app     -e VARIABLE_NAME=server -p 8050:80 -v /home/me/fitly:/app/config ethanopp/fitly:latest
  
  Checking for script in /app/prestart.sh
  Running script /app/prestart.sh
  Running inside /app/prestart.sh, you could add migrations to this file, e.g.:
  
  #! /usr/bin/env bash
  
  # Let the DB start
  sleep 10;
  # Run migrations
  alembic upgrade head
  
  {"loglevel": "info", "workers": 8, "bind": "0.0.0.0:80", "workers_per_core": 2.0, "host": "0.0.0.0", "port": "80"}
  Traceback (most recent call last):
    File "/usr/local/bin/gunicorn", line 8, in <module>
      sys.exit(run())
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 58, in run
      WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/base.py", line 228, in run
      super().run()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/base.py", line 72, in run
      Arbiter(self).run()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 58, in __init__
      self.setup(app)
    File "/usr/local/lib/python3.7/site-packages/gunicorn/arbiter.py", line 118, in setup
      self.app.wsgi()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/base.py", line 67, in wsgi
      self.callable = self.load()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 49, in load
      return self.load_wsgiapp()
    File "/usr/local/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 39, in load_wsgiapp
      return util.import_app(self.app_uri)
    File "/usr/local/lib/python3.7/site-packages/gunicorn/util.py", line 358, in import_app
      mod = importlib.import_module(module)
    File "/usr/local/lib/python3.7/importlib/__init__.py", line 127, in import_module
      return _bootstrap._gcd_import(name[level:], package, level)
    File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
    File "<frozen importlib._bootstrap>", line 983, in _find_and_load
    File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
    File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
    File "<frozen importlib._bootstrap_external>", line 728, in exec_module
    File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
    File "/app/src/fitly/app.py", line 13, in <module>
      db_startup(app)
    File "/app/src/fitly/__init__.py", line 86, in db_startup
      peloton_auto_bookmark_metric='readiness'
    File "<string>", line 4, in __init__
    File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/state.py", line 433, in _initialize_instance
      manager.dispatch.init_failure(self, args, kwargs)
    File "/usr/local/lib/python3.7/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
      with_traceback=exc_tb,
    File "/usr/local/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 182, in raise_
      raise exception
    File "/usr/local/lib/python3.7/site-packages/sqlalchemy/orm/state.py", line 430, in _initialize_instance
      return manager.original_init(*mixed[1:], **kwargs)
    File "/usr/local/lib/python3.7/site-packages/sqlalchemy/ext/declarative/base.py", line 840, in _declarative_constructor
      "%r is an invalid keyword argument for %s" % (k, cls_.__name__)
  TypeError: 'peloton_auto_bookmark_metric' is an invalid keyword argument for athlete
  
  I was previous getting some configuration errors, but I worked through those, and I'm now at this error. Happy to provide any additional info/ Thanks!