v3.5.7

This release incorporates a couple of bug fixes.

• Fixes the bash completion script to support calling 'swupd' with an
  absolute path (e.g. /usr/bin/swupd).
• Improve behavior of 'update' when crossing a minversion, when
  potentially many update artifacts only have their "last update" field
  modified. For these artifacts, 'update' will now avoid downloading
  fresh copies, thus improving performance times for an update.