hub 2.5.1

• hub issue create: ignore the .github/ISSUE_TEMPLATE directory instead of crashing

• hub pull-request: avoid re-requesting reviewers in case of CODEOWNERS

• hub ci-status: handle cases when Checks API is unavailable, like older GitHub Enterprise

• Handle HTTP 422 message format from server response

• Ignore crash for malformed ~/.config/hub file

• Clarify hub init -g documentation that it doesn't imply hub create

• hub clone: add more documentation about git protocol used