Create the validate manifest functionality

[NickGlenn]

This ticket requires 2 parts:

1. A utility function for running over a given manifest object and ensuring that the schema is correct. May also apply defaults or provide "linting" warnings as needed.
2. Hook up the helpme validate command to run the utility function mentioned above on a target manifest file. Will probably need to add the loadManifest task to this operation to help locate the manifest file if a directory is provided as target.

[NickGlenn]

Linting / validation should also have some sort of suggestion strategy for sudo commands.

[NickGlenn]

Additional warnings to add...

• **/* should not be acceptable
• Copying the helpful manifest file should be warned against as well