repo_index should be case insensitive

lib/git/repo_index.sh

@@ -149,7 +149,7 @@ function _rebuild_git_index() {
   IFS=$'\n'
   for repo in $(echo -e "$(_find_git_repos)\n$(echo $GIT_REPOS | sed "s/:/\\\\n/g")"); do
     echo $(basename $repo | sed "s/ /_/g") $repo
-  done | sort | cut -d " " -f2- > "$GIT_REPO_DIR/.git_index"
+  done | sort | cut -d " " -f2- | tr '[A-Z]' '[a-z]' > "$GIT_REPO_DIR/.git_index"
   IFS=$' \t\n'
 
   if [ "$1" != "--silent" ]; then