Merge pull request #168 from hypriot/case-insensitive-xz

Make xz compression check case insensitive

flash

@@ -573,7 +573,7 @@ if [[ -z $CONFIGURE_ONLY ]] ; then
  echo "Use ${image}"
  fi
 
- if [[ "$(file "${image}")" == *"xz compressed data"* ]]; then
+ if [[ "$(file "${image}" | tr '[:upper:]' '[:lower:]' )" == *"xz compressed data"* ]]; then
  command -v xz 2>/dev/null || error "Error: unzip not found. Aborting" 1
  echo "Uncompressing ${image} ..."
  xz -d "${image}" -c >/tmp/image.img