remove old lock files so that upgrades don't get stuck

check_for_update.sh

@@ -44,6 +44,9 @@ fi
 # Cancel upgrade if git is unavailable on the system
 whence git >/dev/null || return 0
 
+# Clean up old lock files
+find $DOTFILES/update.lock -mmin 60 -exec rm  {} \; &>/dev/null
+
 if mkdir "$DOTFILES/update.lock" 2>/dev/null; then
     if [ -f ~/.dotfiles-update ]; then
       . ~/.dotfiles-update