add a generic copyFile routine to ssh.js

lib/ssh.js

@@ -95,3 +95,8 @@ exports.makePristine = function(host, cb) {
   var cmd = 'ssh -o "StrictHostKeyChecking no" ec2-user@' + host + " './pristinify.sh'";
   passthrough(child_process.exec(cmd, cb));
 };
+
+exports.copyFile = function(host, user, local, remote, cb) {
+  var cmd = 'scp -o "StrictHostKeyChecking no" "' + local + '" ' + user + '@' + host + ':"' + remote +'"';
+  child_process.exec(cmd, cb);
+};