Remove usage of url.patterns as per Django's deprecation warnings.

mayan/apps/rest_api/urls.py

@@ -1,20 +1,18 @@
 from __future__ import unicode_literals
 
-from django.conf.urls import patterns, url
+from django.conf.urls import url
 
 from .views import APIBase, APIAppView, BrowseableObtainAuthToken
 
 
-urlpatterns = patterns(
-    '',
-)
+urlpatterns = [
+]
 
-api_urls = patterns(
-    '',
+api_urls = [
     url(r'^$', APIBase.as_view(), name='api_root'),
     url(r'^api/(?P<path>.*)/?$', APIAppView.as_view(), name='api_app'),
     url(
         r'^auth/token/obtain/$', BrowseableObtainAuthToken.as_view(),
         name='auth_token_obtain'
     ),
-)
+]