Log Message:
hub: Update to 2.13.0

Changes:
2.13.0
------
  * New command: hub gist
  * Add git pr show --format=... flag
  * Add hub api --obey-ratelimit flag
  * hub help: support compressed man pages
  * Add hub release download --include=PATTERN flag
  * hub help: Enable hub help --web <command>
  * hub release: Retry attaching release assets on 5xx server errors
  * hub pr checkout fixes
      + handle case when the PR given matches the current branch
      + avoid overriding existing branch merge config
  * hub release: Fail fast when attempting to attach unavailable files
  * Honor HTTPS_PROXY, NO_PROXY environment variables
  * Strip "co-authored-by" lines when populating PR body from git log
  * git compatibility: have hub <cmd> --help open the man page
  * hub fork bash completion improvements
  * hub pr fish completion improvements

2.12.8
------
  * hub compare: improve upstream branch detection & error messages
  * hub compare: allow slash character in branch names
  * hub api: fix GraphQL requests made to Enterprise hosts
  * Docs: clarify --message, --file, and --edit flags

2.12.7
------
  * Fix password prompt on Windows