add workaround to get uuid on macOS

uuid.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# https://gist.github.com/markusfisch/6110640
+
+# Generate a pseudo UUID
+uuid()
+{
+    local N B C='89ab'
+
+    for (( N=0; N < 16; ++N ))
+    do
+        B=$(( $RANDOM%256 ))
+
+        case $N in
+            6)
+                printf '4%x' $(( B%16 ))
+                ;;
+            8)
+                printf '%c%x' ${C:$RANDOM%${#C}:1} $(( B%16 ))
+                ;;
+            3 | 5 | 7 | 9)
+                printf '%02x-' $B
+                ;;
+            *)
+                printf '%02x' $B
+                ;;
+        esac
+    done
+
+    echo
+}
+
+if [ "$BASH_SOURCE" == "$0" ]
+then
+    uuid
+fi