old_contents: from django.conf.urls import url
  from api import views
  
  urlpatterns = [
      url(r'^machines/(?P<serial>.+)/$', views.machine_detail),
      url(r'^inventory/(?P<serial>.+)/$', views.machine_inventory),
      url(r'^machines/$', views.machine_list),
      url(r'^facts/(?P<serial>.+)/$', views.facts),
      url(r'^conditions/(?P<serial>.+)/$', views.conditions),
      url(r'^business_units/(?P<pk>.+)/$', views.business_unit),
      url(r'^business_units/$', views.business_unit_list),
      url(r'^machine_groups/(?P<pk>.+)/$', views.machine_group),
      url(r'^machine_groups/$', views.machine_group_list),
  ]
  
new_contents: from django.conf.urls import url
  from api import views
  
  urlpatterns = [
      url(r'^machines/(?P<serial>.+)/inventory/$', views.machine_inventory),
      url(r'^machines/(?P<serial>.+)/$', views.machine_detail),
      url(r'^machines/$', views.machine_list),
      url(r'^facts/(?P<serial>.+)/$', views.facts),
      url(r'^conditions/(?P<serial>.+)/$', views.conditions),
      url(r'^business_units/(?P<pk>.+)/$', views.business_unit),
      url(r'^business_units/$', views.business_unit_list),
      url(r'^machine_groups/(?P<pk>.+)/$', views.machine_group),
      url(r'^machine_groups/$', views.machine_group_list),
  ]
  
subject: Revert "Think this url is causing issues"