Tweak create/destroy friendship test.

Added a bit of sleep time between destroy and create
requests to allow Twitter time to process.

[ci skip]

README.md

 Tweepy [![Build Status](https://travis-ci.org/tweepy/tweepy.png)](https://travis-ci.org/tweepy/tweepy)
 ======
-A Python library for accessing the Twitter API.
+*Twitter for Python!*
 
 Installation
 ------------

tests.py

@@ -115,6 +115,10 @@ class TweepyAPITests(unittest.TestCase):
         enemy = self.api.destroy_friendship('twitter')
         self.assertEqual(enemy.screen_name, 'twitter')
 
+        # Wait 5 seconds to allow Twitter time
+        # to process the friendship destroy request.
+        sleep(5)
+
         friend = self.api.create_friendship('twitter')
         self.assertEqual(friend.screen_name, 'twitter')