Validation of MCF files

[alexandreleroux]

Feature request. (moved from the to-do list to the issue tracker)

Would be useful to have a validation mechanism for MCF files. Validating things such as: MCF syntax, missing non-optional values based on schema, duplicate base_mcf, etc

[alexandreleroux]

Now that pygeometa has moved to the yaml format for its MCFs, the following tools might be useful to fulfill this feature request? https://github.com/Grokzen/pykwalify and https://github.com/adrienverge/yamllint

[alexandreleroux]

The validation of MCF files should be done while considering the stated MCF version. See #85

[alexandreleroux]

To investigated (suggested by a colleague): jsonschema could be used to validate the MCF content once it's imported as a Python dictionary.

[alexandreleroux]

Big thanks @tomkralidis for the initial implementation!

Seems like the current validation code does not work when pygeometa's nesting feature is used in an MCF. Do you foresee a solution? Merci !