Improved exception message.

Before: ```Unknown message type "johndoe". Available are [foobar].```

After: ```Unknown message type "johndoe". Available are [foo,bar].```
Merge pull request #22 from blaugueux/patch-2

Improved exception message.
Added php-amqplib support
Allow any registered provider
Moved php-amqplib to suggest
Merge pull request #24 from ThisIsAreku/amqplib

Added php-amqplib support
Fixed the DI configuration

This fixes a mistakes introduced in #24.
Closes #25
Merge pull request #26 from stof/fix_config

Fixed the DI configuration
Add a retry-attempts option.
Merge pull request #28 from antoox/add-retry-attempts-option

Add a retry-attempts option.
Prepare new version
Merge pull request #29 from odolbeau/prepare-new-verison

Prepare new version
Fix the retry attempts number when no option is defined.
Do not check whether the retry-attempts option exists.
Merge pull request #31 from antoox/hotfix-retry-attempts

Fix the retry attempts number when no option is defined.
Add ability to configure consumer default queue
Merge pull request #34 from adrienbrault/consumer-default-queue

Add ability to configure consumer default queue
Update README.md

Use correct YAML comments. This may reduce some WTF for people that copy paste the default configuration to get started
Merge pull request #35 from baldurrensch/patch-1

Update README.md
Fix readme example syntax