Fail git status if .git not in cwd or parent directory

lib/git/helpers.sh

@@ -0,0 +1,8 @@
+function find_in_cwd_or_parent() {
+  local slashes=${PWD//[^\/]/}; local directory=$PWD;
+  for (( n=${#slashes}; n>0; --n )); do
+    test -e "$directory/$1" && echo "$directory/$1" && return 0
+    directory="$directory/.."
+  done
+  return 1
+}