added key disableHostKeyChecking that if set to true will cause smart…

…copy to bypass the built-in SSH host key checks. This is useful if you dont want to worry about the known host file across reboots. If this key doesnt exist or is false, it is the admins responsibility to ensure the known hosts file is up to date

configuration.json.example

@@ -5,6 +5,7 @@
   "backupDestinationBasePath": "tank",
   "backupConfigurationDestinationPath": "tank/configs",
   "backupDestinationPrivateKeyPath": "/opt/backup_id_rsa",
+  "disableHostKeyChecking":true,
   "transferStrategy":"mbuffer",
   "snapshotIdentifier":"smartcopy",
   "mBufferLocalPath":"/opt/smartcopy/bin/mbuffer",

lib/endpoint.js

@@ -20,6 +20,14 @@ Endpoint.prototype.sshCmd = function(){
     cmdParts.push('-i');
     cmdParts.push(this.privateKeyPath);
   }
+  if ( config.disableHostKeyChecking === true){
+    cmdParts.push(
+      '-o',
+      'UserKnownHostsFile=/dev/null',
+      '-o',
+      'StrictHostKeyChecking=no'
+    );
+  }
   var destination = '';
   if ( this.username != null ){
     destination += this.username + "@";