Update vendor crypto package (solves ssh agent issue)

[coopernurse]

This week I was writing a Supfile and hit this error:

dialer failed ssh: handshake failed: ssh: disconnect, reason 2: Too many authentication failures
connecting to clients failed: connecting to remote host failed: Connect("root@165.22.152.199:22"): ssh: handshake failed: ssh: disconnect, reason 2: Too many authentication failures

I was able to fix this by adding this line to ssh.go:

config.HostKeyCallback = ssh.InsecureIgnoreHostKey()

But that's only available in more recent versions of the crypto package.

Is there any objection to updating the crypto deps?