Add haveibeenpwned to functions Docker prefix

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

sample-functions/stack.yml

@@ -38,7 +38,7 @@ functions:
   haveibeenpwned:
     lang: go
     handler: ./haveibeenpwned
-    image: haveibeenpwned:latest
+    image: functions/haveibeenpwned:0.1
   hostnameintent:
     lang: dockerfile
     handler: ./hostnameintent