title: Remove leading zeros from MAC address
body: <p>I have a MAC address that looks like this.</p>
  
  <p><code>01:AA:BB:0C:D0:E1</code></p>
  
  <p>I want to convert it to lowercase and strip the leading zeros.</p>
  
  <p><code>1:aa:bb:c:d0:e1</code></p>
  
  <p>What's the simplest way to do that in a Bash script?</p>