Merge branch 'feature/test-helpers' of github.com:IvanChepurnyi/EcomDev_PHPUnit into feature/test-helpers

Minor features release that introduces dispatching of events and updated composer.json file

! Added events to test listener. Now possible to add observers to PHPUnit application initialization

Update composer.json

According to the README.md the extension requires PHPUnit 3.7.*, so
let's show it in the composer.json file. Also update
magento-composer-installer required version in order to make this
extension compatiable with other Magento extension installed via
composer.

Virtual File System, Custom Fixtures Path, New Yaml Loader, Custom Fixture Processors