HOT-FIX: altera inclusão de drf-yasg

Configura urls drf-yasg se ele está presente na lista de apps do projeto

sapl/api/urls.py

@@ -1,7 +1,5 @@
 from django.conf import settings
 from django.conf.urls import include, url
-from drf_yasg import openapi
-from drf_yasg.views import get_schema_view
 from rest_framework import permissions
 from rest_framework.routers import DefaultRouter
 
@@ -29,26 +27,29 @@ for app, built_sets in SaplApiViewSetConstrutor._built_sets.items():
 
 urlpatterns_router = router.urls
 
-
-schema_view = get_schema_view(
-    openapi.Info(
-        title="Sapl API - docs",
-        default_version='v1',
-        description="Sapl API  - Docs - Configuração Básica",
-    ),
-    url=settings.SITE_URL,
-    public=True,
-    permission_classes=(permissions.AllowAny,),
-)
-
-urlpatterns_api_doc = [
-    url(r'^docs/swagger(?P<format>\.json|\.yaml)$',
-        schema_view.without_ui(cache_timeout=0), name='schema-json'),
-    url(r'^docs/swagger/$',
-        schema_view.with_ui('swagger', cache_timeout=0), name='schema-swagger-ui'),
-    url(r'^docs/redoc/$',
-        schema_view.with_ui('redoc', cache_timeout=0), name='schema-redoc'),
-]
+urlpatterns_api_doc = []
+if 'drf_yasg' in settings.INSTALLED_APPS:
+    from drf_yasg import openapi
+    from drf_yasg.views import get_schema_view
+    schema_view = get_schema_view(
+        openapi.Info(
+            title="Sapl API - docs",
+            default_version='v1',
+            description="Sapl API  - Docs - Configuração Básica",
+        ),
+        url=settings.SITE_URL,
+        public=True,
+        permission_classes=(permissions.AllowAny,),
+    )
+
+    urlpatterns_api_doc = [
+        url(r'^docs/swagger(?P<format>\.json|\.yaml)$',
+            schema_view.without_ui(cache_timeout=0), name='schema-json'),
+        url(r'^docs/swagger/$',
+            schema_view.with_ui('swagger', cache_timeout=0), name='schema-swagger-ui'),
+        url(r'^docs/redoc/$',
+            schema_view.with_ui('redoc', cache_timeout=0), name='schema-redoc'),
+    ]
 
 # TODO: refatorar para customização da api automática
 deprecated_urlpatterns_api = [