Fix django urls import (#343)

* fixing deprecated import

* fix for django in python 2.7

* skip pymongo map_reduce test when testing on latest pymongo versions since the map_reduce functionality has been removed

tests/apps/app_django.py

@@ -9,8 +9,11 @@
 import time
 import opentracing
 import opentracing.ext.tags as ext
+try:
+    from django.urls import re_path
+except ImportError:
+    from django.conf.urls import url as re_path
 
-from django.conf.urls import url
 from django.http import HttpResponse, Http404
 
 filepath, extension = os.path.splitext(__file__)
@@ -123,9 +126,9 @@ def complex(request):
 
 
 urlpatterns = [
-    url(r'^$', index, name='index'),
-    url(r'^cause_error$', cause_error, name='cause_error'),
-    url(r'^another$', another),
-    url(r'^not_found$', not_found, name='not_found'),
-    url(r'^complex$', complex, name='complex')
+    re_path(r'^$', index, name='index'),
+    re_path(r'^cause_error$', cause_error, name='cause_error'),
+    re_path(r'^another$', another),
+    re_path(r'^not_found$', not_found, name='not_found'),
+    re_path(r'^complex$', complex, name='complex')
 ]

tests/clients/test_pymongo.py

@@ -6,6 +6,7 @@
 import json
 import unittest
 import logging
+import pytest
 
 from nose.tools import (assert_is_none, assert_is_not_none,
                         assert_false, assert_true, assert_list_equal)
@@ -18,6 +19,10 @@
 
 logger = logging.getLogger(__name__)
 
+pymongoversion = pytest.mark.skipif(
+    pymongo.version_tuple >= (4, 0), reason="map reduce is removed in pymongo 4.0"
+)
+
 
 class TestPyMongoTracer(unittest.TestCase):
     def setUp(self):
@@ -169,6 +174,7 @@ def test_successful_aggregate_query(self):
         payload = json.loads(db_span.data["mongo"]["json"])
         assert_true({"$match": {"type": "string"}} in payload, db_span.data["mongo"]["json"])
 
+    @pymongoversion
     def test_successful_map_reduce_query(self):
         mapper = "function () { this.tags.forEach(function(z) { emit(z, 1); }); }"
         reducer = "function (key, values) { return len(values); }"