Delete SQS message if unmarshalling fails (RichardKnop#504)

* Delete SQS message if unmarshalling fails

* Fix failing unit test

Merge pull request RichardKnop#446 from Sh4d1/multiple_aqmp

Add options for multiple amqp brokers

Merge pull request RichardKnop#482 from Martin91/fix-#122-deadlock

fix: an possible deadlock in amqp broker's consume()

Update README.md

Merge pull request RichardKnop#464 from RichardKnop/fix-mongodb-backe…

…nd-factory-test-issue

fix: fixed a unit test which actually tried to connect to mongo

Merge pull request RichardKnop#453 from charleswhchan/charleswhchan-p…

…atch-1

Fix typo in config.go

Merge pull request RichardKnop#440 from RichardKnop/fix-sqs-panic

fixed panic in SQS broker

Merge pull request RichardKnop#434 from bharat-p/433-expose-sqs-recei…

…pt-handle

Re:433 Expose SQS ReceiptHandle in task signature

Merge pull request RichardKnop#420 from Martin91/master

use routing key as both queue name and binding key

Merge pull request RichardKnop#410 from bitpeng/expiretime

the default expire time is 1 day, not 1 hour