Add Behat tests for SonataClassificationBundle APIs

Fix classification Behat tests to have a full workflow

Remove method files

Update FeatureContext
Merge pull request #321 from eko/classification

Add Behat tests for SonataClassificationBundle APIs
Updated behat test to avoid regression from https://github.com/sonata-project/ecommerce/pull/191
Test to assert we may remove several elements from basket through quantity
Merge pull request #328 from Bladrak/invoiceAddressBehat

Updated behat test to avoid regression from https://github.com/sonata-project/ecommerce/pull/191
Merge pull request #329 from Bladrak/removeSeveralBasket

Test to assert we may remove several elements from basket through quantity
Add SonataPageBundle API Behat tests
Merge pull request #330 from eko/page

Add SonataPageBundle API Behat tests
Fixing incorrect link format
Add user & group Behat tests features

Update group features
Merge pull request #326 from eko/user

Add user & group Behat tests features
Added Write API Media test & various fixes
Add Behat tests for products APIs
Merge pull request #334 from eko/product

Add Behat tests for products APIs
Merge pull request #333 from Bladrak/apiWriteMedia

Added Write API Media test & various fixes
Add Serializer configuration and Behat tests for Basket APIs

Add Basket Behat tests
Merge pull request #335 from eko/basket

Add Serializer configuration and Behat tests for Basket APIs
Switched to db-stored basket
Implemented https://github.com/sonata-project/ecommerce/pull/155
Added CONTRIBUTING.md file