ruby-rdf/shex: Release 0.6.4
- Use ShEx 2.1 Grammar
- Import and some other features not yet implemented
- BracketedTripleExpr now allows any TripleExpression, not just OneOf/EachOf.
- Validate that numeric facets can only be used on datatypes derived from a numeric type.
- Consolidate some structure validation logic.
- Simplify satisfies? matcher to not need to match specific results on failure, for now.
- Don't do new structure validation for referenced labels, for now. This potentially depends on limiting the search to not go through a TripleConstraint.
- Move 'sxp' dependency to shex.rb. Relates to #4.
- Fix examples to run. Fixes #4.