ref: e5560786a4ddbde7b6b1fc5e869bb3ef4e8b9126 dhall-ruby/test d---------
Allow imports to be either binary or source form
Update to latest dhall-lang
Add cache_key test runner
Anything we'll eventually run is a skip
Fix test to new binary format

No more null fragment
Use upstreamed type tests
Simplify binary tests for now
Fix style in tests
Forgot to add this file
Refactor Optional/None typecheck
Refactor Function annotate
Run tests per docs
Use path like names in more tests
Implement integrity checks
Working typechecker
Type inference/checking about half done

Passing unit tests for features implemented so far
Support headers for HTTP import
Binary encoding

Every AST node uses as_json to express the generic structure for
encoding itself.  Expression aliases as_cbor to as_json by default and
then uses as_cbor in to_cbor (aliased as to_binary).

This design is because we need to override the encoding of Double for
CBOR, but want to keep the normal Float value for as_json in case that
is used directly (to avoid surprising the user).
If trying to import from IPFS, fallback to gateway