fix middleware process response template_name based on https://github…

.travis.yml

@@ -1,25 +1,19 @@
 language: python
 python:
-  - "3.5"
-  - "3.4"
-  - "3.3"
+  - "3.6"
   - "2.7"
 env:
   - DJANGO_VERSION=1.11
-  - DJANGO_VERSION=1.10
-  - DJANGO_VERSION=1.9
-  - DJANGO_VERSION=1.8
 services:
   - mysql
   - postgresql
 matrix:
   exclude:
-    - python: "3.3"
+    - python: "2.7"
       env: DJANGO_VERSION=1.9
-    - python: "3.3"
+    - python: "2.7"
       env: DJANGO_VERSION=1.10
-    - python: "3.3"
-      env: DJANGO_VERSION=1.11
+
 install:
   - pip install -r requirements.txt
   - pip install -q Django==$DJANGO_VERSION

django_prometheus/middleware.py

@@ -141,8 +141,9 @@ def process_view(self, request, view_func, *view_args, **view_kwargs):
                 name, transport, method).inc()
 
     def process_template_response(self, request, response):
-        responses_by_templatename.labels(str(
-            response.template_name)).inc()
+        if hasattr(response, 'template_name'):
+            responses_by_templatename.labels(str(
+                response.template_name)).inc()
         return response
 
     def process_response(self, request, response):