Delete a Tag

[hannahhall]

As an admin I would like to be able to delete a Tag so that I can remove any that are not needed.

Given an admin is vising the list of Tags
When they select the Delete option
Then they should be prompted to confirm the deletion

Given the admin wishes to confirm the delete
When they the select the option to confirm
Then the Tag should be removed from the system
And the admin should be directed back to the Tag list

Given the admin decides not to confirm the delete
When they the select the option to reject confirmation
Then the Tag should NOT be removed from the system
And the admin should be directed back to the Tag list

NOTE: For the time being it is acceptable to treat all users as admin users. There is a future story about enforcing user permissions.