FIFO queues

[elliotchance]

SQS now supports FIFO queues: http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/FIFO-queues.html which have some major differences.

Existing (what they now called "standard") queues cannot be converted to FIFO, the same should be true in fake_sqs as well.

[cladden]

@tiwilliam are there any approaches to having fake_sqs support a FIFO queue?

[tiwilliam]

@cladden TBH, I haven't spent any time looking in to what it would mean in terms of design. All I know is that we already "guarantee" single delivery and order.

[jinghuaz]

hava play to design?FIFO