Exception happens when browsing to local development instance of /budget/ route

[MikeTheCanuck]

When browsing to http://127.0.0.1:8000/budget/ after following the instructions (1) - (5) in the project README.md, the following output is rendered by the runserver app server:

(budget_venv) Mikes-MacBook-Pro15:team-budget mike$ ./budget_proj/manage.py runserver
Performing system checks...

System check identified no issues (0 silenced).
October 28, 2017 - 00:37:58
Django version 1.10.5, using settings 'budget_proj.settings.dev'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
[28/Oct/2017 00:38:01] "GET /budget/ HTTP/1.1" 200 13873
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 49979)
Traceback (most recent call last):
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/hub.py", line 864, in switch
    assert getcurrent() is self.hub, "Can only use Waiter.switch method from the Hub greenlet"
AssertionError: Can only use Waiter.switch method from the Hub greenlet
Sat Oct 28 00:38:01 2017 <io at 0x103395e48 fd=8 events=READ> failed with AssertionError

[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/css/screen.css HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/css/reset.css HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/object-assign-pollyfill.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/jquery-1.8.0.min.js HTTP/1.1" 304 0
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socketserver.py", line 639, in process_request_thread
    self.finish_request(request, client_address)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socketserver.py", line 361, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socketserver.py", line 696, in __init__
    self.handle()
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/django/core/servers/basehttp.py", line 159, in handle
    self.raw_requestline = self.rfile.readline(65537)
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/jquery.slideto.min.js HTTP/1.1" 304 0
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/socket.py", line 586, in readinto
    return self._sock.recv_into(b)
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/_socket3.py", line 385, in recv_into
    self._wait(self._read_event)
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/css/toolbar.css HTTP/1.1" 304 0
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/_socket3.py", line 157, in _wait
    self.hub.wait(watcher)
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/hub.py", line 651, in wait
    result = waiter.get()
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/jquery.wiggle.min.js HTTP/1.1" 304 0
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/hub.py", line 899, in get
    return self.hub.switch()
  File "/Users/mike/code/team-budget/budget_venv/lib/python3.6/site-packages/gevent/hub.py", line 630, in switch
    return RawGreenlet.switch(self)
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/handlebars-2.0.0.js HTTP/1.1" 304 0
gevent.hub.LoopExit: ('This operation would block forever', <Hub at 0x10338fc28 select pending=0 ref=0>)
----------------------------------------
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/jquery.ba-bbq.min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/js-yaml.min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/lodash.min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/backbone-min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/swagger-ui.min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/jsoneditor.min.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/highlight.9.1.0.pack.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/highlight.9.1.0.pack_extended.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/marked.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/lib/swagger-oauth.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/init.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/js/jquery_pre.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/js/jquery_post.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/js/toolbar.js HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/images/logo_small.png HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/img/ajax-loader.gif HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/css/print.css HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/static/debug_toolbar/css/print.css HTTP/1.1" 304 0
[28/Oct/2017 00:38:01] "GET /budget/?format=openapi HTTP/1.1" 200 10012
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/images/favicon-32x32.png HTTP/1.1" 200 1654
[28/Oct/2017 00:38:01] "GET /budget/static/rest_framework_swagger/images/favicon-16x16.png HTTP/1.1" 304 0'

Repro conditions:

• Python version 3.6.3
• using default local SQLite database configuration