title: How can I define Content-type in Swift using NSURLSession
body: <p>I want to set content-type in my below code to call web api.
  Content-type will be  <code>application/json; charset=utf-8</code></p>
  
  <pre><code>let url = NSURL(string: "http:/api/jobmanagement/PlusContactAuthentication?email=\(usr)&amp;userPwd=\(pwdCode)")
  
  println("URL:  \(url)")
  
  let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {
      (data, response, error) in
      println(NSString(data: data, encoding: NSUTF8StringEncoding))
  }
  
  //  task.setValue(&lt;#value: AnyObject?#&gt;, forKey: &lt;#String#&gt;)
  task.resume()
  </code></pre>