Merge pull request #19 from yassirh/master

Moved meta from the entities to the api classes & improved the specs.
Add support GuzzleAdapter and Customise Exception.

** Modify original file with No BC. **
Update BuzzAdapter
Update composer.json
update BuzzAdapter
update BuzzAdapterSpec
rollback BuzzAdapter
Remove GuzzleAdapter

Guzzle V4.* No compatible with PHP 5.3
Merge pull request #20 from liverbool/master

[PR] Add support GuzzleAdapter and Allow customize exception.