Fix deploy script

Add hide-from-log-file param to the deploy script, otherwise the private SSH key will be exposed in the log files.  There's an example here:
https://github.com/opennebraska/staging-site/blob/98b8c2ae7ea5d89c2bdd55f15819e4c8f337ff47/wercker.yml
Merge pull request #4 from natebenes/patch-1

Hide ssh key from logs