Exit Gracefully with deprecated manifest/deployment yaml

We have been seeing more and more of SIGSEGV lately for two reasons, (1) whisk deploy running with deprecated YAML schema (2) more and more developers using whisk deploy 😄

As @Juice10 pointed out, it will be cleaner if whisk deploy exits gracefully instead of running into segmentation violation error when run with deprecated schema. Adding this kind of error reporting might not be trivial but at least lets try and determine scope of it.