Replace deprecated Point.get_coords() calls

This works as far back as Django 1.8, which is the earliest which we
support.

See django-haystack#1454

Author: acdha

haystack/fields.py

@@ -223,7 +223,7 @@ def prepare(self, obj):
             return None
 
         pnt = ensure_point(value)
-        pnt_lng, pnt_lat = pnt.get_coords()
+        pnt_lng, pnt_lat = pnt.coords
         return "%s,%s" % (pnt_lat, pnt_lng)
 
     def convert(self, value):

haystack/models.py

@@ -127,7 +127,7 @@ def _get_distance(self):
             if not hasattr(self, self._point_of_origin['field']):
                 raise SpatialError("The field '%s' was not included in search results, so the distance could not be calculated." % self._point_of_origin['field'])
 
-            po_lng, po_lat = self._point_of_origin['point'].get_coords()
+            po_lng, po_lat = self._point_of_origin['point'].coords
             location_field = getattr(self, self._point_of_origin['field'])
 
             if location_field is None:

test_haystack/test_managers.py

@@ -87,7 +87,7 @@ def test_order_by_distance(self):
         self.assertIn('distance_point', params)
         self.assertDictEqual(params['distance_point'], {'field': 'location',
                                                          'point': p})
-        self.assertTupleEqual(params['distance_point']['point'].get_coords(), (1.23, 4.56))
+        self.assertTupleEqual(params['distance_point']['point'].coords, (1.23, 4.56))
 
         self.assertListEqual(params['sort_by'], ['distance'])