* * append to "config" and "known_hosts" instead of overwriting
* * refactor options
* * add test
* * fix test
* * print created files twice
* * print the contents of known_hosts and config
* * fix revision for test
* * fix revision
* * add LF to known_hosts / config
* * append LF to config and known_hosts
* * fix test
* * reject overwriting private-key and public-key
* * update test (will cause error)
* * revert verify.yml
* * update README and CHANGELOG
* * fix example in README
* * update CHANGELOG