v0.3.2

Changelog

d0ab879 Add SSH certificate expiry date to metrics
32c6452 Add per-host metrics
670c7bf Build with Go 1.12
83edaeb Clean up idle HTTP connections before reconnect
c72cc5c Close response bodies in tests
3b14ebc Respect known_hosts file
e0e656f Update dependencies
be1b27d Update dependencies
2810035 update dependencies