title: golang: convert 16-byte uuid into 32 bytes
body: <p>I'm trying to save a uuid as a Memo field on a Stellar transaction.  The memo field will take a string of 28 bytes or less; (as a string, a uuid is 36 bytes, so that won't work).  It can also take a hash of 32 bytes.  As bytes a uuid is 16 bytes.</p>
  <p>So I'm wondering if there's a way to convert my uuid into a byte type that is 32 bytes?</p>