Use an alternate hook for django 1.9

Author: pglombardo

setup.py

@@ -18,6 +18,7 @@
                         'basictracer>=2.2.0',
                         'psutil>=5.1.3'],
       entry_points={'django': ['django.core.handlers.base = instana.django:hook'],
+                    'django19': ['django.core.handlers.base = instana.django19:hook'],
                     'flask': ['flask.cli = instana.flaskana:hook'],
                     'runtime': ['string = instana.runtime:hook']},
       test_suite='nose.collector',