Change receive_messages_from_queue's max_count to 10

It doesn't make a lot of sense to default max_count to 1, since one can
also receive a single message with receive_message_from_queue. The name
of the method also implies that it returns multiple messages, so having
it default to returning 1 message is a bit counterintuitive.

src/sqs_poller/sqs_poller.py

@@ -93,11 +93,11 @@ def purge_queue(self, queue_name):
         queue = self.get_queue_by_name(queue_name)
         return queue.purge()
 
-    def receive_messages_from_queue(self, queue_name, max_count=1, **receive_kwargs):
+    def receive_messages_from_queue(self, queue_name, max_count=10, **receive_kwargs):
         """Return maximum of `max_count` messages from a queue named `queue_name`.
 
         :param str queue_name: Name of the queue.
-        :param int max_count: Maximum number of messages to receive.
+        :param int max_count: Maximum number of messages to receive (10 at most).
         :param receive_kwargs: Arguments that will be passed to the underlying
          `receive_messages` call.
         :raise QueueDoesNotExist: When the queue is not found, this exception is raised.