Connect with username in Sylius

                    
|Q            |A   |
|---          |--- |
|Bug Fix?     |n   |
|New Feature? |Y   |
|BC Breaks?   |n   |
|Deprecations?|n   |
|Tests Pass?  |n   |
|Fixed Tickets|#471|
|License      |MIT |
|Doc PR       |na  |