title: ssh key errors when trying to connect a worker
body: <p>I'm trying to set up concourse for the first time. I went through tutorials and was successful getting concourse running in vagrant and the hello world demo.  I want to know set up worker, for now this is all on my local machine, to do iOS builds. I can't seem to get the right ssh keys set. I keep getting:</p>
  
  <pre><code>{"timestamp":"1499972495.137019873","source":"worker","message":"worker.beacon.restarting","log_level":2,"data":{"error":"failed to dial: failed to construct client connection:%!(EXTRA *errors.errorString=ssh: handshake failed: remote host public key mismatch)","session":"3"}}```
  </code></pre>
  
  <p>I generated my local worker keys per the tutorial, and found the keys in the vagrant vm at <code>/opt/concourse</code>. However, any public keys I copy from the server for the TSA key don't seem to match what's expected.</p>
  
  <p>Am I having trouble because I’m running the lite version from the tutorial?</p>
  
  <p>Are the keys in <code>/opt/concourse</code> ones I want to use?</p>