pykek repository no longer exists

[decal]

Output from running brew upgrade on macOS High Sierra with Homebrew 1.7.1:

==> Upgrading sidaf/pentest/pykek 
==> Cloning https://github.com/bidord/pykek
Cloning into '/Users/decal/Library/Caches/Homebrew/pykek--git'...
remote: Repository not found.
fatal: repository 'https://github.com/bidord/pykek/' not found
Error: An exception occurred within a child process:
  DownloadError: Failed to download resource "pykek"
Failure while executing; `git clone https://github.com/bidord/pykek /Users/decal/Library/Caches/Homebrew/pykek--git` exited with 128. Here's the output:
Cloning into '/Users/decal/Library/Caches/Homebrew/pykek--git'...
remote: Repository not found.
fatal: repository 'https://github.com/bidord/pykek/' not found