title: Looking for a swift way to generate OAuth 1 signature
body: <p>I'm working on a small swift program to work with Yelp API over <strong>OAuth-1</strong>. I am looking to generate a HMAC-SHA1 signature.</p>
  
  <p>I have the customer key, secret key , token and token secret.</p>
  
  <p>From what I know, to make an API request with OAuth 1, we need the following attributes : </p>
  
  <ol>
  <li>oauth_consumer_key</li>
  <li>oauth_token </li>
  <li>oauth_signature_method = (HMAC-SHA1)</li>
  <li>oauth_signature</li>
  <li>oauth_timestamp</li>
  <li>oauth_nonce</li>
  </ol>
  
  <p>How do I generate #4,5,6</p>
  
  <p>I looked other <a href="https://stackoverflow.com/questions/4084979/ruby-way-to-generate-a-hmac-sha1-signature-for-oauth">this</a>, but didn't help.</p>
  
  <p>TIA!</p>