* openssh_keypair: bugfix make regenerating keypairs via force possible / add invalid file handling
* openssh_keypair: change permissions of read-only file instead of deleting it for regeneration; add changelog fragment
* address review feedbak, refactor
* add integration tests for bigfixes
* linter: fix indent
* fixup integration tests: use force when regenerating an invalid file
* linter: fix indent
* openssh_keypair: address review feedback
* openssh_keypair: fixup, remove backtick
* openssh_keypair: address review feedback
* Only pass 'y' into stdin of ssh-keygen when file exists.
