title: how to check the csv contain a specific column header in ruby using fastercsv
body: <p>I have a csv file contains values as: </p>
  
  <pre><code>"UID","NAME","USERNAME","ROLE","ADDRESS"
  12,"Joe","joe_123","A","address1"
  13,"Lee","lee_321","U","address2"
  </code></pre>
  
  <p>I need to check existence of column heading <code>"UID"</code> and <code>"USERNAME"</code> in the csv file. I am using ruby and fastercsv gem. </p>
  
  <p>Please help me how to write this checking using fastercsv. Thanks in advance</p>