Use `git clone --shared` and avoid almost all filesystem work

roles/coopdevs.org/files/post-receive

@@ -3,7 +3,7 @@ GIT_REPO=$HOME/repos/coopdevs.github.io.git
 TMP_GIT_CLONE=$HOME/tmp/git/coopdevs.github.io
 PUBLIC_WWW=/opt/sites/coopdevs
 
-git clone $GIT_REPO $TMP_GIT_CLONE
+git clone --shared $GIT_REPO $TMP_GIT_CLONE
 jekyll build --source $TMP_GIT_CLONE --destination $PUBLIC_WWW
 rm -Rf $TMP_GIT_CLONE
 exit