Make tests compatible with client<=0.4 again

Author: korfuri

django_prometheus/middleware.py

@@ -1,6 +1,5 @@
 import django
 from prometheus_client import Counter, Histogram
-from prometheus_client.utils import INF
 
 from django_prometheus.utils import Time, TimeSince, PowersOf
 
@@ -49,7 +48,7 @@ def process_response(self, request, response):
     buckets=(.01, .025, .05, .075,
              .1, .25, .5, .75,
              1.0, 2.5, 5.0, 7.5,
-             10.0, 25.0, 50.0, 75.0, INF))
+             10.0, 25.0, 50.0, 75.0, float("inf")))
 requests_unknown_latency = Counter(
     'django_http_requests_unknown_latency_total',
     'Count of requests for which the latency was unknown.')

requirements.txt

@@ -1,7 +1,7 @@
 Django>=1.8
 django-redis>=4.8
 pep8>=1.6.2
-prometheus-client>=0.0.21,<0.4.0
+prometheus-client>=0.0.21
 pip-prometheus>=1.1.0
 mock>=1.0.1
 mysqlclient<1.4