Merge pull request #736 from legokichi/issue735

Issue735

tweepy/api.py

@@ -259,6 +259,20 @@ class API(object):
             require_auth=True
         )
 
+    @property
+    def unretweet(self):
+        """ :reference: https://dev.twitter.com/rest/reference/post/statuses/unretweet/%3Aid
+            :allowed_param:'id'
+        """
+        return bind_api(
+            api=self,
+            path='/statuses/unretweet/{id}.json',
+            method='POST',
+            payload_type='status',
+            allowed_param=['id'],
+            require_auth=True
+        )
+
     @property
     def retweets(self):
         """ :reference: https://dev.twitter.com/rest/reference/get/statuses/retweets/%3Aid