"Strawberry [inputs] Forever" aka front end fixes

In this PR:
+ Changed root to Warwick for usability testing
+ Changed z-index of edit_student and edit_contact sections so that the inputs can be clicked into when validation errors show up
+ Fixed width of language inputs so that the positioning doesn't jump when someone makes a selection
+ Disable the z-index of the edit_contact section if the user clicks the guardian_relationship modal. It was getting stuck on the modal-fade.
+ Fixed positioning of the next and previous buttons

@plusjeff Ready for review