validation process about weblogic-deploy-tooling

[robertpatrick]

The validateModel tool is intended to help the model author so it is really meant to use interactively. The exit code 0 in this case means that the software worked and completed correctly, even though it may have found validation errors. Both createDomain and deployApps call validation before performing any work and will exit with a non-zero exit code if the artifacts passed to it are not valid.

As discussed, I think this is sufficient unless we find a use case where we need to run validateModel in a non-interactive mode.