Update API vies and serializers for the latest Django REST framework version. Replace DRF Swagger with DRF-YASG.

Signed-off-by: Michael Price <loneviking72@gmail.com>

mayan/urls.py

@@ -3,12 +3,32 @@ from __future__ import unicode_literals
 from django.conf import settings
 from django.conf.urls import include, url
 from django.contrib import admin
+from django.utils.translation import ugettext_lazy as _
+
+from drf_yasg import openapi
+from drf_yasg.views import get_schema_view
+from rest_framework import permissions
+
+import mayan
 
 admin.autodiscover()
+schema_view = get_schema_view(
+   openapi.Info(
+      title=_('%s API') % mayan.__title__,
+      default_version='v2',
+      description=mayan.__description__,
+      license=openapi.License(name=mayan.__license__),
+   ),
+   validators=['flex', 'ssv'],
+   public=True,
+   permission_classes=(permissions.AllowAny,),
+)
 
 urlpatterns = [
     url(r'^admin/', admin.site.urls),
-    url(r'^docs/', include('rest_framework_swagger.urls')),
+    url(r'^swagger(?P<format>.json|.yaml)$', schema_view.without_ui(cache_timeout=None), name='schema-json'),
+    url(r'^swagger/$', schema_view.with_ui('swagger', cache_timeout=None), name='schema-swagger-ui'),
+    url(r'^redoc/$', schema_view.with_ui('redoc', cache_timeout=None), name='schema-redoc'),
 ]
 
 if settings.DEBUG: