yaml validator for presentations.yaml

[castrojo]

We need a validator for presentations.yaml before we open it up to submissions.

[cjyabraham]

As part of this make the slides parameter required since I key off of it during the import.

[castrojo]

What do we do in cases where there's no slides, video only? Do we just make having slides a prerequisite?

[cjyabraham]

We had previously discussed making the slides field required. I am now keying off that field during the import process. If we don't make it required, then I'll need to key off some other field that is always required and guaranteed to be unique for each presentation. Alternatively, I could come up with some kind of composite field, made up of video + slides fields, to use as a unique key. Any thoughts?

[jeefy]

@cjyabraham I'd do slides+date as a composite field. We don't currently require videos (but if we could I can add that too and we can add that to said composite field)