fix: Initialize the

This lets us reference the global store of spans for requests and so on

django_opentracing/middleware.py

@@ -1,5 +1,5 @@
 from django.conf import settings
-from django_opentracing.tracer import initialize_global_tracer, DjangoTracer
+from django_opentracing.tracer import initialize_global_tracer
 try:
     # Django >= 1.10
     from django.utils.deprecation import MiddlewareMixin
@@ -20,7 +20,7 @@ def __init__(self, get_response=None):
         '''
         self.get_response = get_response
         initialize_global_tracer()
-        self._tracer = DjangoTracer()
+        self._tracer = settings.OPENTRACING_TRACER
 
     def process_view(self, request, view_func, view_args, view_kwargs):
         # determine whether this middleware should be applied

django_opentracing/tracer.py

@@ -118,6 +118,7 @@ def initialize_global_tracer():
             tracer_callable = getattr(settings, 'OPENTRACING_TRACER_CALLABLE', 'opentracing.Tracer')
             tracer_parameters = getattr(settings, 'OPENTRACING_TRACER_PARAMETERS', {})
             opentracing.tracer = import_string(tracer_callable)(**tracer_parameters)
+            settings.OPENTRACING_TRACER = DjangoTracer()
         initialize_global_tracer.complete = True