Headers.Valid() fails on sets with InteractionFields as the header

[zacsketches]

The InteractionFields headers do not pass the Valid() test and therefore RecordSets generated by the solution cannot be opened for further processing.

Headers valid may be too brittle at this point to include in the package. As some point when the package gains more widespread use we might have enough knowledge to apply a Valid() check. However, the current version is a user protection that does not serve a useful purpose for the early adopters who understand their data.

At this point, since the use user community is so small I think the right thing to do is remove Valid(). The other option is to make Valid() a no-op and keep it in the repo for future implementation.

[zacsketches]

Instead of the valid() function that is checked for a set of headers I think I'd like to move to a RecordSet.Validate(format FileFormat). The FileFormat argument is a series of constants that can be validated against. These constants provide a []string of required headers that must be in be in the file in order for it to validate against that format.

This still requires getting rid of the Valid() function.

[zacsketches]

Closed by commit e27027b.