Copy image signing resources into docker filesystem

[Alex-Carter01]

Resources such as the policy.json and cosign.pub used to verify a signed image need to be copied into the docker environment to get used.

Signed-off-by: Alex Carter Alex.Carter@ibm.com

[dubek]

Also note that as-is the resources directory is empty. The addition (copying it into the simple-kbs image) is only meaningful if someone puts their resource files in it before building the image.

[fitzthum]

56 should fix CI issues btw

[fitzthum]

Please rebase @Alex-Carter01