(maint) Add some useful ssh options

When sshing to transient VMs it's super useful to ignore host key
checking. These options will make sure the host keys for the VMs are not
being checked and that they are not getting added to your existing known
hosts file.

lib/vmfloaty/ssh.rb

@@ -30,7 +30,8 @@ class Ssh
       end
 
       hostname = "#{response[host_os]["hostname"]}.#{response["domain"]}"
-      cmd = "#{ssh_path} #{user}@#{hostname}"
+      ssh_options= ["-oStrictHostKeyChecking=no", "-oUserKnownHostsFile=/dev/null"]
+      cmd = "#{ssh_path} #{ssh_options.join(' ')} #{user}@#{hostname}"
 
       # TODO: Should this respect more ssh settings? Can it be configured
       #       by users ssh config and does this respect those settings?