Add a test to the modal spec to ensure that the .mercury-modal and .mercury-modal-overlay elements get reused by all modals opened after the first one.
Add a test to the modal spec to ensure that the .mercury-modal and .mercury-modal-overlay elements get reused by all modals opened after the first one.

bonekost/mercury,bonekost/mercury,shilpi230/mercury,Senhordim/mercury,mervick/mercury,sarink/mercury,twistir/mercury_cms,bonekost/mercury,larquin/mercury,tcv-nguyen/spree-mercury,mediatainment/mercury,twistir/mercury_cms,Senhordim/mercury,mediatainment/mercury,sarink/mercury,mervick/mercury,tcv-nguyen/spree-mercury,larquin/mercury,larquin/mercury,Senhordim/mercury,mediatainment/mercury,sarink/mercury,mervick/mercury,shilpi230/mercury,shilpi230/mercury