Commands from the README don't work, quiver integration broke the master probably

首先使用 ./manage.py migrate 重现 README 中的命令，并沿着 traceback 读取到 swapi_graphene/urls.py，尤其关注 import graphql.backend.quiver_cloud。将 README 中描述的设置与该 import 所需的依赖项进行比较；当全新的设置能够在不出现所报告的 ImportError 的情况下运行文档中记载的迁移时，即表示完成。

• Python version: Python 2.7.12
• Operating System: Ubuntu 16.04

Description

I ran the commands from the README. The migrate failed, look at the backlog below. When I revert commit 5d92929640c6280ffd8f4f56f6f2361b4246939b it works. Quiver integration broke the master probably.

What I Did

user@server$ ./manage.py migrate
Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/base.py", line 327, in execute
    self.check()
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/base.py", line 359, in check
    include_deployment_checks=include_deployment_checks,
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 62, in _run_checks
    issues.extend(super(Command, self)._run_checks(**kwargs))
  File "/home/user/.local/lib/python2.7/site-packages/django/core/management/base.py", line 346, in _run_checks
    return checks.run_checks(**kwargs)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/checks/registry.py", line 81, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/checks/urls.py", line 16, in check_url_config
    return check_resolver(resolver)
  File "/home/user/.local/lib/python2.7/site-packages/django/core/checks/urls.py", line 26, in check_resolver
    return check_method()
  File "/home/user/.local/lib/python2.7/site-packages/django/urls/resolvers.py", line 254, in check
    for pattern in self.url_patterns:
  File "/home/user/.local/lib/python2.7/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/user/.local/lib/python2.7/site-packages/django/urls/resolvers.py", line 405, in url_patterns
    patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/home/user/.local/lib/python2.7/site-packages/django/utils/functional.py", line 35, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/home/user/.local/lib/python2.7/site-packages/django/urls/resolvers.py", line 398, in urlconf_module
    return import_module(self.urlconf_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/user/.ssh/swapi-graphene/swapi_graphene/urls.py", line 27, in <module>
    from graphql.backend.quiver_cloud import GraphQLQuiverCloudBackend
  File "/home/user/.local/lib/python2.7/site-packages/graphql/backend/quiver_cloud.py", line 5, in <module>
    "requests package is required for Quiver Cloud backend.\n"
ImportError: requests package is required for Quiver Cloud backend.
You can install it using: pip install requests