allows to delete providers too

bin/account-manager.pl.in

@@ -225,6 +225,12 @@ sub list_providers {
         $provider->print();
     }
 
+    if ($options{delete}) {
+        foreach my $provider (@$providers) {
+            $provider->delete() or die "failed to delete authentication token\n";
+        }
+        printf "%d providers removed\n", scalar @$providers;
+    }
 }
 
 sub list_tokens {
@@ -351,6 +357,7 @@ S<B<--contact> I<string>>
 S<[B<--displayname> I<string>]>
 
 B<account-manager-client.pl> B<list_providers>
+[B<--delete>]
 
 B<account-manager-client.pl> B<list_tokens>
 S<B<--sp_entityid> I<string>>