title: Get current year and month (and next month) in this format YYYYMM in Ruby
body: <p>How do I get the current date and month in Ruby in a specific format?</p>
  
  <p>If today is June, 8th of 2012, I want to get <code>201206</code>.</p>
  
  <p>And also, I would like to be able to get the next month from the one we are in, taking into account that in <strong>201212</strong>, the next month would be <strong>201301</strong>.</p>