title: Swagger - Adding multiple security parameters to the same schema definition
body: <p><strong><em>Aim</em></strong></p>
  
  <p>To include multiple security headers to every request made within the API</p>
  
  <p><strong><em>Problem</em></strong></p>
  
  <p>I am trying to add multiple headers to my Swagger YAML security definitions.
  I have trawled though the API but not have alot of luck
  But am finding that when making the 'Try-This-Operation' I am required to select one. Rather than able to use both. Is this correct or am I doing something incorrectly?</p>
  
  <p><strong><em>Snippet</em></strong></p>
  
  <pre><code>securityDefinitions:
    userEmail:
      type: apiKey
      name: User Email
      in: header
    clientId:
      type: apiKey
      name: Client Id
      in: header
  
  security: [ { userEmail: [], clientId: []  } ]
  </code></pre>
  
  <p><strong><em>Alternative?</em></strong></p>
  
  <p>If I am trying to do this impossible ... 
  Is it possible to specify these parameters as default for all the rest paths within the swagger document?</p>
  
  <p>I am new to Swagger this week any have found everything else without problem ... but I cannot find any good example of this.</p>
  
  <p>If any guidance could be given that would be incredibly helpful 
  Many thanks </p>