User Story #5: Owner deletes group

[CassandraNewell]

As an authenticated user
I want to delete a writer group I created
Because fuck those guys

Acceptance criteria:

• User can access Delete button from group show page
• After clicking, user is prompted to confirm before group deletion
• Upon confirmation, group is deleted and user is redirected to their main page
• If user does not confirm, group is not deleted and user remains on group show page