Includes general improvements, bug fixes and support for GitHub Enterprise v2.13.1

• Retry with the admin ssh port on network unreachable too. Retry with the admin ssh port on network unreachable too. #377
• Output backup utils version on backup and restore Output backup utils version on backup and restore #384
• Check filesystem supports hardlinks Check filesystem supports hardlinks #388
• Switch back to optimised restore route calculation Switch back to optimised restore route calculation #389
• Optionally log verbose output to a file instead of stdout Optionally log verbose output to a file instead of stdout #391
• Switch back to optimised backup route calculation Switch back to optimised backup route calculation #392
• Remove check for git from ghe-ssh Remove check for git from ghe-ssh #393
• Use remote's mktemp to create temp dir on remote host Use remote's mktemp to create temp dir on remote host #395

/cc @github/backup-utils