Fix for new Set#=== in newer Ruby
Because breaking things is point releases is how Ruby rolls.
Minitest fail fast for unit tests
Simplify Natural/subtract on x === y
Implement dependent types, assert : A === B
LetBlock is just sugar now and not part of the AST
This includes the new record selection inspection optimizations.
Some test setup tweaks in dhall-lang
Fix alpha normalization on normalize tests
Normalize multiline string literal line endings
Fix stack level too deep for single quote string
Specialize the visitor since we only use it one place
Do not start IO work until asked
Update resolve tests to test actually valid cases