Add confirmation for Patron Group Deletion

Purpose:
To add a confirmation that the deletion of a patron group has successfully occurred.

Scenarios:

1. Scenario [See comment below about the order of the buttons]
   • Given the Delete button/icon on Settings > Users > Patron group
   • When clicked
   • Then a window will pop up asking user to confirm the deletion or cancel the deletion as shown here: https://drive.google.com/file/d/0By8ccf5VV4EWZkRSVXc2cE1IbmM/view?usp=sharing
     • Header: Delete patron group? CB: Please use sentence case, despite the title case used in the mock-ups
     • Body: <patronGroupName> will be removed from patron groups.
     • Buttons: Cancel, Delete
2. Scenario
   • Given the Delete button on Settings > Users > Patron groups> “Delete patron group?” confirmation window
   • When clicked
   • Then the patron group will be deleted and a confirmation will appear after the deletion has occurred reading, "The patron group <patronGroupName> was successfully deleted." See https://drive.google.com/file/d/0By8ccf5VV4EWVTlzZFVaTExGLVU/view?usp=sharing
3. Scenario
   • Given the Cancel button on the patron group confirmation window
   • When clicked
   • Then the patron group will not be deleted and the user will be returned to the Settings > Users > Patron groups

Out of Scope: Undo