Operations to perform:
  Apply all migrations: auth, sessions, admin, contenttypes, sklep
Running migrations:
  Applying sklep.0002_auto_20150228_2138...Traceback (most recent call last):
  File "C:\Program Files (x86)\JetBrains\PyCharmPro4.0.4\helpers\pycharm\django_manage.py", line 41, in <module>
    run_module(manage_file, None, '__main__', True)
  File "C:\Python34\lib\runpy.py", line 182, in run_module
    return _run_module_code(code, init_globals, run_name, mod_spec)
  File "C:\Python34\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "C:\Python34\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:/Users/Emil/Dropbox/sklep_z_serwetkami\manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 533, in handle
    return self.handle_noargs(**options)
  File "C:\Python34\lib\site-packages\django\core\management\commands\syncdb.py", line 27, in handle_noargs
    call_command("migrate", **options)
  File "C:\Python34\lib\site-packages\django\core\management\__init__.py", line 115, in call_command
    return klass.execute(*args, **defaults)
  File "C:\Python34\lib\site-packages\django\core\management\base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "C:\Python34\lib\site-packages\django\core\management\commands\migrate.py", line 161, in handle
    executor.migrate(targets, plan, fake=options.get("fake", False))
  File "C:\Python34\lib\site-packages\django\db\migrations\executor.py", line 68, in migrate
    self.apply_migration(migration, fake=fake)
  File "C:\Python34\lib\site-packages\django\db\migrations\executor.py", line 102, in apply_migration
    migration.apply(project_state, schema_editor)
  File "C:\Python34\lib\site-packages\django\db\migrations\migration.py", line 108, in apply
    operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
  File "C:\Python34\lib\site-packages\django\db\migrations\operations\fields.py", line 37, in database_forwards
    field,
  File "C:\Python34\lib\site-packages\django\db\backends\sqlite3\schema.py", line 176, in add_field
    self._remake_table(model, create_fields=[field])
  File "C:\Python34\lib\site-packages\django\db\backends\sqlite3\schema.py", line 74, in _remake_table
    self.effective_default(field)
  File "C:\Python34\lib\site-packages\django\db\backends\schema.py", line 187, in effective_default
    default = field.get_db_prep_save(default, self.connection)
  File "C:\Python34\lib\site-packages\django\db\models\fields\related.py", line 1735, in get_db_prep_save
    return self.related_field.get_db_prep_save(value, connection=connection)
  File "C:\Python34\lib\site-packages\django\db\models\fields\__init__.py", line 627, in get_db_prep_save
    prepared=False)
  File "C:\Python34\lib\site-packages\django\db\models\fields\__init__.py", line 907, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:\Python34\lib\site-packages\django\db\models\fields\__init__.py", line 915, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: 'None'