Reduce precision of lat/long coords used in testing

Python 2 truncates earlier than Python 3 when converting floats to a
string, which was causing problems with the cassette recording.

tests/test_api.py

@@ -407,7 +407,7 @@ class TweepyAPITests(TweepyTestCase):
         # Test various API functions using Austin, TX, USA
         self.assertEqual(self.api.geo_id(id='1ffd3558f2e98349').full_name, 'Dogpatch, San Francisco')
         self.assertTrue(place_name_in_list('Austin, TX',
-            self.api.reverse_geocode(lat=30.267370168467806, long= -97.74261474609375))) # Austin, TX, USA
+            self.api.reverse_geocode(lat=30.2673701685, long= -97.7426147461))) # Austin, TX, USA
 
     @tape.use_cassette('testsupportedlanguages.json')
     def testsupportedlanguages(self):