implement /danger/delete-snapshot defroute (back-end in web.lisp).

src/web.lisp

@@ -1707,8 +1707,12 @@
                      (utils:set-alert "No Snapshot Name provided." "missing-data")
                      (redirect "/danger/manage-snapshots"))
                     ;; Check snapshot exists here...
+                    ((not (storage:raw-directory-exists?
+                            (format nil "snapshots/~a/" snapshot-name)))
+                     (utils:set-alert "Cannot find selected Snapshot." "invalid-data")
+                     (redirect "/danger/manage-snapshots"))
                     (t
-                     ;; (snapshot:delete-snapshot)
+                     (snapshot:delete-snapshot snapshot-name)
                      (utils:set-alert "Snapshot deleted." "success")
                      (redirect "/danger/manage-snapshots")))
 	      ;; Not Authorised