message: Clarify SHA check comment.
diff: @@ -23,7 +23,7 @@ cd fixtures
  while read -r repo commitish dir; do
  if [ -f $dir/INSTALLED ] &&
  - # Did we update the fixture commitish since we last ran setup?
  + # Is the SHA for this fixture the same since we last ran setup?
  (cd $dir && [ $(git rev-list -1 $commitish) == $(git rev-list -1 HEAD) ])
  then
  continue
  