keystonemidleware dependency should be > 4.0.0

Right now keystonemiddleware requirement is as follows:

keystonemiddleware!=4.1.0,!=4.5.0,>=4.0.0 # Apache-2.0

Unfortunately, 4.0.0 (which is the minimum) wont work due to a breaking change that changes the _BaseAuthProtocol class to BaseAuthProtocol[0] and that class is used at keystone/middleware/auth.py [1]

This was done in the change from 4.0.0 to 4.1.0 but the requirements were never bumped. Thus using latest keystone from master and keystonemiddleware == 4.0.0 results in failure:

2016-09-13 17:06:05.465591 Traceback (most recent call last):
2016-09-13 17:06:05.465603 File "/usr/bin/keystone-wsgi-admin", line 51, in <module>
2016-09-13 17:06:05.465619 application = initialize_admin_application()
2016-09-13 17:06:05.465624 File "/usr/lib/python2.7/site-packages/keystone/server/wsgi.py", line 132, in initialize_admin_application
2016-09-13 17:06:05.465632 config_files=_get_config_files())
2016-09-13 17:06:05.465636 File "/usr/lib/python2.7/site-packages/keystone/server/wsgi.py", line 69, in initialize_application
2016-09-13 17:06:05.465641 startup_application_fn=loadapp)
2016-09-13 17:06:05.465645 File "/usr/lib/python2.7/site-packages/keystone/server/common.py", line 50, in setup_backends
2016-09-13 17:06:05.465651 res = startup_application_fn()
2016-09-13 17:06:05.465654 File "/usr/lib/python2.7/site-packages/keystone/server/wsgi.py", line 66, in loadapp
2016-09-13 17:06:05.465659 'config:%s' % find_paste_config(), name)
2016-09-13 17:06:05.465663 File "/usr/lib/python2.7/site-packages/keystone/version/service.py", line 53, in loadapp
2016-09-13 17:06:05.465702 controllers.latest_app = deploy.loadapp(conf, name=name)
2016-09-13 17:06:05.465709 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 247, in loadapp
2016-09-13 17:06:05.465841 return loadobj(APP, uri, name=name, **kw)
2016-09-13 17:06:05.465853 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 272, in loadobj
2016-09-13 17:06:05.465868 return context.create()
2016-09-13 17:06:05.465876 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 710, in create
2016-09-13 17:06:05.465897 return self.object_type.invoke(self)
2016-09-13 17:06:05.465903 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 144, in invoke
2016-09-13 17:06:05.465909 **context.local_conf)
2016-09-13 17:06:05.465921 File "/usr/lib/python2.7/site-packages/paste/deploy/util.py", line 55, in fix_call
2016-09-13 17:06:05.465969 val = callable(*args, **kw)
2016-09-13 17:06:05.465980 File "/usr/lib/python2.7/site-packages/paste/urlmap.py", line 31, in urlmap_factory
2016-09-13 17:06:05.466084 app = loader.get_app(app_name, global_conf=global_conf)
2016-09-13 17:06:05.466101 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 350, in get_app
2016-09-13 17:06:05.466124 name=name, global_conf=global_conf).create()
2016-09-13 17:06:05.466138 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 362, in app_context
2016-09-13 17:06:05.466146 APP, name=name, global_conf=global_conf)
2016-09-13 17:06:05.466152 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 450, in get_context
2016-09-13 17:06:05.466171 global_additions=global_additions)
2016-09-13 17:06:05.466177 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 562, in _pipeline_app_context
2016-09-13 17:06:05.466192 for name in pipeline[:-1]]
2016-09-13 17:06:05.466197 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 454, in get_context
2016-09-13 17:06:05.466217 section)
2016-09-13 17:06:05.466243 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 476, in _context_from_use
2016-09-13 17:06:05.466265 object_type, name=use, global_conf=global_conf)
2016-09-13 17:06:05.466272 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 406, in get_context
2016-09-13 17:06:05.466289 global_conf=global_conf)
2016-09-13 17:06:05.466294 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 296, in loadcontext
2016-09-13 17:06:05.466320 global_conf=global_conf)
2016-09-13 17:06:05.466337 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 328, in _loadegg
2016-09-13 17:06:05.466344 return loader.get_context(object_type, name, global_conf)
2016-09-13 17:06:05.466350 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 620, in get_context
2016-09-13 17:06:05.466369 object_type, name=name)
2016-09-13 17:06:05.466375 File "/usr/lib/python2.7/site-packages/paste/deploy/loadwsgi.py", line 646, in find_egg_entry_point
2016-09-13 17:06:05.466393 possible.append((entry.load(), protocol, entry.name))
2016-09-13 17:06:05.466404 File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2355, in load
2016-09-13 17:06:05.466735 return self.resolve()
2016-09-13 17:06:05.466750 File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2361, in resolve
2016-09-13 17:06:05.466772 module = __import__(self.module_name, fromlist=['__name__'], level=0)
2016-09-13 17:06:05.466779 File "/usr/lib/python2.7/site-packages/keystone/middleware/__init__.py", line 15, in <module>
2016-09-13 17:06:05.466835 from keystone.middleware.auth import * # noqa
2016-09-13 17:06:05.466857 File "/usr/lib/python2.7/site-packages/keystone/middleware/auth.py", line 38, in <module>
2016-09-13 17:06:05.466952 class AuthContextMiddleware(auth_token.BaseAuthProtocol):
2016-09-13 17:06:05.466971 AttributeError: 'module' object has no attribute 'BaseAuthProtocol'

A simple fix would be to change the requirement to blacklist 4.0.0

[0] https://review.openstack.org/#/c/255691/
[1] https://github.com/openstack/keystone/blob/master/keystone/middleware/auth.py#L38