title: Change Character spacing in navigation bar title swift
body: <p>I want to change character spacing in navigation bar title. I am trying to use the following code.</p>
  
  <pre><code>let attributedString = NSMutableAttributedString(string: "New Title")
          attributedString.addAttribute(NSKernAttributeName, value:   CGFloat(1.4), range: NSRange(location: 0, length: 9))
  
  
  
          self.navigationItem.title = attributedString
  </code></pre>
  
  <p>This is giving the following error :</p>
  
  <p>Cannot assign a value of type 'NSMutableAttributedString' to a value of type 'string?'</p>
  
  <p>Can someone help me with this or suggest a different way to change character spacing in navigation bar title in swift?</p>