create_subtheme.sh is different to bootstrap barrio

in Bootstrap barrio you have

if [[ "$OSTYPE" == "darwin"* ]]; then
  grep -Rl bootstrap_barrio_subtheme .|xargs sed -i '' -e "s/bootstrap_barrio_subtheme/$CUSTOM_BARRIO/"
else
  grep -Rl bootstrap_barrio_subtheme .|xargs sed -i -e "s/bootstrap_barrio_subtheme/$CUSTOM_BARRIO/"
fi

where as in subtheme you simply have

grep -Rl bootstrap_sass .|xargs sed -i -e "s/bootstrap_sass/$CUSTOM_BOOTSTRAP_SASS/"

My feeling is we need similar in boostrap_sass starter kit otherwise we get unwanted files being added with -e suffix.