EFS Mount Targets not created when ebextension runs...

Hi,

I have noticed that it may happen that your environment is running the ebextensions when the mount targets are not yet created. As such, the update operation fails since the mount-efs.sh script exits due to the mount points not being ready.

I added a sleep 120 in the script to take me out of the immediate issue and it solves it, but it would be good to have some kind of retry logic for that command.