Add validator to client

[vsoch]

The validator should be able to parse a file system and check for correct organization as well as a recipe

[vsoch]

SCIF (the scientific filesystem) is an organizational standard for (internal) organization of containers. A validator, then, should be a module within the client that can basically check that:

• the organization of the /scif/ folder conforms to that described in the specification, with appropriate errors/warnings given when necessary for missing/malformed/extra content.
• (bonus) the recipes included within folders are present and also valid

[vsoch]

For those interested for #hacktoberfest please feel free to ask clarifying questions, etc. So glad for your help!